Can my dates really be THAT far off?-updated #11

[Mama Lo]

I'm 15 wks today. One week ago (14wks) I met with my midwife for the first time, who while feeling my uterus said, "umm, how sure about your dates are you?"
Pretty sure, I was charting.....she said I felt 18-19 wks! She is sending me for my sono in 2 wks, a few weeks early. Hoping to verify it is just one babe and check my dates.
Can I really be that far off? I was charting when we conceived, I had come off the Mirena IUD in Jan, my first 2 cycles were about 45-50 days long with luteal phases of only 4 days. My 3rd cycle, neg preg test 11 dpo, positive test 14 dpo.
Does anyone have charting experience, people around keep saying things like, you can be pregnant and still get your period, etc. But doesn't charting guarantee those kinds of things don't happen??
Here's my chart, if that helps.
http://www.fertilityfriend.com/home/2c2683

[finnegansmom]

your chart is not super duper 100% conviincing to me on that ovulation date, only because there is NO fertile CM at all that cycle which is a little odd. I chart as well, but my CM is a major sign for me - alot before O and turning to creamy within hours it seems. I have gotten pregnant by ONLY going on CM (more than once). You do have a thermal shift, but you might be more of a slow riser and FF is putting your O date a little bit after when you did O (especially on the first cycle).

But that said, i think feeling the fundus is a rather rough approximate way of telling the baby age, nothing set in stone. Some people measure ahead some behind. Maybe it's twins? I don't think requesting a US is too out there, because 4 weeks off might be over her comfort level.
I would feel much much more concerned if you were measuring 4 weeks behind at this point than 4 weeks bigger.

[Ruthla]

From what I can see, you may have ovulated on day 20 rather than on day 24, but 4 days shouldn't make any real difference in the pregnancy (other than when to take a pregnancy test, and you're past that point already.)

Yes, you can have vaginal bleeding while pg- so I took a look at the previous month as well. First of all, I'm not convinced you really ovulated that month at all- the temps aren't all that much higher than some of the ones earlier in the month. And I just don't think you'd have 4 days of "normal menstrual flow" while pg. A little spotting is normal, maybe a day or two of light flow, but it looks to me like you really did menstruate on April 17th. Besides, if you'd conceived around April 12th, you wouldn't have gotten the negative HPT on May 21st.

I think that having an ultrasound to see if there's more than one baby in there is a reasonable idea. If you're planning to have an u/s anyway, having it a bit sooner because you're measuring off sounds wise. If you're opposed to ultrasounds, then you can diagnose twins much later in pg by feeling for more than one head.

[~Demeter~]

I didn't look at your chart but I wanted to tell you that yes!! you can measure 'ahead' and still be right on about your dates. I typically measure WAY ahead until my uterus fills the lower portion of my abdomen. Once I hit about 16ish weeks then I start to measure a little closer to dates but I'm still anywhere from 2-3 weeks 'ahead' by standard measurement. If you are certain of your dates then there's really no reason for an earlier u/s.

[faithfulmama]

For what it's worth with both of my pregnancies my uterus measured ahead enough that my midwife wanted to rule out twins. With my first it was something like 4 weeks ahead for 2 or 3 months. Then with my second I measured a full 8 weeks ahead for the majority of the pregnancy, starting in the first trimester. I was positive on my dates, and both were singletons born at 41 weeks.

[MaerynPearl]

I measured ahead early on and slowly evened out to measuring right on with DD... it can be normal. It can also be a possible sign of twins (though I would think it would be more than 4 weeks off at that point if twins)

the US will help the midwife by letting her know there is only one baby in there (and not to be checking for two heartbeats each time) and that indeed you did not ovulate a month earlier than your chart says (you would be surprised, but this does happen. And Ive seen pregnant women get negative tests.)

[~Demeter~]

Measuring ahead early on isn't an accurate assessment of twins or really much of anything. If I recall it's only accurate in your first pregnancy and only after 20-something weeks... a lot of care providers place a huge emphasis on fundal measurement but they are often horribly inaccurate. It's nice to have a measurement to go off of to chart growth but I think it's terrible how much emphasis is placed on it... because it causes so many women stress, especially in those earlier weeks.

[JessieBird]

Analyzing pregnancy tests is totally not scientific but just because no one else has asked, I will - how dark was your test on the 24th? If it was faint to 1/2 the darkeness of the control line, I'd say there's a good chance that your chart is fairly accurate, though I agree that without a few more signs to go by (like CM) pinpointing ovuation to the day is impossible. If the test was super dark and came up quickly, then it's possible that you in fact ovulated the cycle prior and your test on the 21st was faulty. I'm grasping at straws though and a lot of people would poopoo this kind of analysis. I just don't have any tests of my own to obsess over right now...

As for fundal height, my MWs don't put any stock in it at all until after 20 weeks. With DS they said I felt big and indeed he measured ahead throughout pregnancy, though not big enough to throw my dates into question, and was born at 39w looking fully cooked. With this pregnancy, I've measured small in the MWs office, small enough for them to recommend an extra ultrasound at 26w to compare growth to my 20w US. Sure enough, ultrasound showed everything measuring right on target with the dates on my chart.

From what I understand, one "measurement" done either by feel or with a measuring tape is totally meaningless, especially in the first half of pregnancy. Keep us posted though! It would be so fun to find out that you have a month less to wait to meet your baby!

[dejagerw]

I chart, and actually from your chart, I'd estimate your due date to be January 5. So yes, to me your estimation may be off and your midwife may be correct. How did you estimate your due date from your chart? I use the rule where you take the first day of temperature rise from the thermal shift, subtract 7 days and add 9 months.

[MaerynPearl]

Originally Posted by dejagerw

I chart, and actually from your chart, I'd estimate your due date to be January 5. So yes, to me your estimation may be off and your midwife may be correct. How did you estimate your due date from your chart? I use the rule where you take the first day of temperature rise from the thermal shift, subtract 7 days and add 9 months.

thats not a very reliable way of doing it... considering it puts you 4 weeks ahead of where it should be! You would be induced for being overdue 2 weeks before you are even due!

According to her chart, both going by ovulation day and subtracting 14 days from ovulation and making that LMP, she is due Jan 31st

Doing it with mine would put me due Aug 13th, but trust me, I am due Sept 14th!

[dejagerw]

WHOOPS!!,


I just looked at the chart again, and it looks like I thought the temperature shift happened on April 12, when it really was May 12. (Sorry!!) So, based on that, I'd say your due date is actually February 5.

And just in case anyone is thinking I'm randomly making up this calculation of due date, I'm not. It's actually called the Prem rule. While no formula is exactly 100% (since there are normal variations in the time of gestation), a study found this formula to have 69% of births within 7 days before or after the Prem EDC, 81% within 10 days, and 100% within 12 days before and 9 days after the Prem EDC.

According to my NFP literature, your upward thermal shift gives you the single most accurate way of dating the time of conception. (Since you can't precisely pinpoint ovulation from fertility signs like mucus, since in reality it can occur as early as 3 days before or 3 days after Peak Day.)

My own personal date last pregnancy predicted exactly the date I went into labor.

I hope this helps, sorry for the confusion earlier!!

[Mama Lo]

Originally Posted by finnegansmom

your chart is not super duper 100% conviincing to me on that ovulation date, only because there is NO fertile CM at all that cycle which is a little odd.

That's part of why I was asking, I was still nursing when I had my mirena removed. So my first pp period was 50 days after the mirena removal. During the 3 cycles I had before bfp, I never had any cf pattern and certainly no fertile cf. I figured I wasn't ovulating or wasn't fertile. I was surprised when I got the bfp, because I thought it was going to take longer since no cf

Originally Posted by finnegansmom

] I don't think requesting a US is too out there, because 4 weeks off might be over her comfort level.
I would feel much much more concerned if you were measuring 4 weeks behind at this point than 4 weeks bigger.

I'm not opposed to us and we're waiting 2 weeks, so that hopefully it will be the only one we'll need. I'll be 17 weeks, should be far enough for growth & developement.

[Mama Lo]

Originally Posted by JessieBird

Analyzing pregnancy tests is totally not scientific but just because no one else has asked, I will - how dark was your test on the 24th? If it was faint to 1/2 the darkeness of the control line, I'd say there's a good chance that your chart is fairly accurate, though I agree that without a few more signs to go by (like CM) pinpointing ovuation to the day is impossible. If the test was super dark and came up quickly, then it's possible that you in fact ovulated the cycle prior and your test on the 21st was faulty. I'm grasping at straws though and a lot of people would poopoo this kind of analysis. I just don't have any tests of my own to obsess over right now...

I actually thought about that this morning. The first test was a dollar store test. The second test was a first response something.... and it lit up almost immediately, and was a dark line. The pregnant line lit up before the control line! But like you, I thought well I could prob spend all day coming up with all these maybe's, ya know?

[dejagerw]

Originally Posted by Mama Lo

That's part of why I was asking, I was still nursing when I had my mirena removed. So my first pp period was 50 days after the mirena removal. During the 3 cycles I had before bfp, I never had any cf pattern and certainly no fertile cf. I figured I wasn't ovulating or wasn't fertile. I was surprised when I got the bfp, because I thought it was going to take longer since no cf

To me, it does look like you ovulated this chart, because you do have an obvious thermal shift. (Aside from the wonky temps on the 6th and 22nd.) And although you didn't detect what you thought was "more fertile" mucus, any mucus observed should be considered "fertile". If you don't mind me asking, how do you observe your mucus? Externally or internally?

Twins could be a possibility, however. And when you do get your ultrasound, just beware that it won't predict accurate dates (since only early ultrasounds can predict dates well.) If I were you, I would still go with your chart dates. (so either the January 31 you estimated, or February 5th using the rule I mentioned earlier).

[Mama Lo]

Thanks for all the input ladies! I know I might just be measuring ahead right now, my mom said that with all of her pregnancies the docs always tried to tell her she was farther along than she knew she was. I was just surprised by it, cuz with dd I was always behind a few weeks, but then she was 9 days early
I'm just looking for some reassurance with my chart. Since I never really developed a pattern before I got pregnant, I'm not confidant in my charting skills, kwim? I was pretty all over the place after having the Mirena removed, so I never expected to get the bfp when we did. I never experience that fertile cf, I was pretty consistantly creamy or dry
And of course everyone that I talk to about it, always wants to tell me I'm wrong. And that I must just be wrong about my dates
But with charting, our body doesn't lie, right? I mean according to my temps only, including the shift for o, and then 2nd shift for pregnancy doesn't that signal that I would have HAD to conceived that cycle? Regardless if I'm off a few days or so with o.....

[Adamsmama]

This happened to me this pg ... at 13 weeks my m/w said I was measuring around 18 weeks. She sent me for an u/s to check for twins and it is just one baby ...

[Mama Lo]

Had my u/s yesterday! Baby's measurments dated me 17w 1d, and according to my dates I was 17 weeks! I'm surprised it dated me to close! That's great news, I was just preparing for the horror stories of u/s dating weeks earlier and then facing opposition. But none of that here!
ETA...just one baby...a boy

[trimestersdoula]

Glad you got some answers. When I was pregnant with DS the doctor checked with a doppler at around 10 weeks. Couldn't find a heartbeat. She sent me for an ultrasound. I was 11 weeks along. When the tech put the wand on me she said "oh, this is why your doctor couldn't find the heartbeat. Baby is way up by your belly button." So my fundus was measuring 20ish weeks and baby was measuring 11w2d. I asked her to check and make sure there was only one in there. Yep. Just one.
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[Baby~Braatens~Mama]

Congratulations on your baby boy! I have been following your thread but didn't know what to say... I am so happy things worked out for you!

[HulaJenn]

First, congrats!
I wanted to add (a little late I know) that especially since you've had 1 baby already, the uterus already "knows where it is supposed to go" so it is very common for 2nd and up pregnancies to measure ahead.