Cycle, timing, EDD question for those that are cycle experts (Mae, I know you are out there! ;))

[DeChRi]

I am mostly just curious, as subsequent children tend to come earlier. Also knowing that this always is not the case, if my theory is correct, it could still mean nothing for when this baby will come. That being said....

From when I hit puberty, I remember knowing that each month I would start a few days after I did the month before. THat was about all I knew. DD1 came as a surprise when I was 20. I was given an EDD of 4/16 based on LMP. She came 4/20. 9 yrs between DD1 and DD2. In between I didn't pay a lot of attention to my cycles. DD1 nursed 4 years and AF didnt show for 3 of those. I do know that my cycles were still a bit longer than a month, but never tracked and didn't know what it mattered. DD2s conception was easy, without charting help. EDD was 11/11 based on LMP. Went into labor with her 11/9 and she came a few min past midnight on the 10th.

So we decide to have baby #3. I had an IUD between #2 and #3, it came out around June. I had 1 period, then 40 days, then another. I started temping and tracking at this point as this was our first month to try. I got to day cd 18 with no temp change and no change to OPK. I scrapped em for a couple days, DH and I dtd daily just for kicks. I peed on my last OKP around 20 and had a a potential positive, but not sure if I had missed it or what.

I started testing on cd28, cd34 came and went, no BFP. We were bummed, had a pitcher or margaritas on a great date night and decided we would get em next month. I had a ton of tests so I kept peeing daily. Day 36, last test, BFP.

So based on this info, I am guessing that I probably have always ovulated well past the normal cd14. Does this sound accurate? And if that is that case, then if my OB for my pats two kids had come up with a true EDD based on ovulation, it would have been several days later than based on LMP, correct? Which would really mean that DD1 probably came on time and DD2 probably came many days early.

I ask because this time I adjusted my LMP date to tell the OB on when I thought I ovulated. Early sono matched that exactly to the EDD. So this new babe's EDD is based on a pretty accurate ovulation date I believe. Had they gone off true LMP, her EDD would have been a week sooner.

So I always thought that my DD1 came "late" and DD2 "right on time", but I now think that DD1 came "right on time" and DD2 came a week or so "early". And if the trend of subsequent kiddos coming a bit sooner holds true, then this babe could (in theory) come a good week before EDD. Now she could also come two weeks late and the whole story above would mean nothing, lol.

But mainly I am trying to make sense of my body and cycles and understand it all. Does the above make sense? It is late here and this thought just rolled across my brain.

[dmpmercury]

It sounds like your cycles were always a little longer than 28 day cycles. So say your cycle length was 34 or 35 it could be a whole week later than the day 14 that they estimate and 28 day cycle from. If you never charted it hard to pinpoint what you lp is but it probably would be between 12-16 days. You don't always ovulate on the same day every month so it really hard to say what cycle day you got pregnant with your first two kids without an early u/s to confirm dates and those can be off a few days in either direction too.

[newmommy7-08]

You are correct in your thinking. Doctors charts predict EDD w/ a standard 28 day cycle. If you have a longer or a shorter cycle than that they should adjust, but many don't. DS on a 28 day cycle would have been due 7/5. On my cycle had a EDD of 7/9 (32 day cycle that month) but was born on 6/18. Apparently women in my family typically have babies around 37 weeks. My gram waited till after I had him to remember that all 5 of her births were at 37 weeks and so were my moms 2.

[MaerynPearl]

did you do all the calculations to find out your previous EDDs with the alterations left in?

if you had average 33 day cycles (my assumption as AF always came a few days later each month)... you would assume O happened on cd19 (not 100% going to be the case... but is most likely closer than assuming cd14)

so you would add 5 days to your original LMP (or, really, to the EDD) and assume that is more correct.

Now that said... theres nothing to say this one will not come sooner OR later than the previous one (and while possible is not likely to go longer than the first)

because my cycles are not normal (and I know it... I have been charting for quite some time as you know) i had to adjust my LMP... but only by one day... to get the correct EDD for my O date.

[kalamos23]

Well - I have gotten pregnant on normal and longer cycles - so it just depends on when you Oed. With DD, I actually Oed for once on CD14 (normally I Oed 16-19) so her EDD was actually true from my LMP. With this one, I Oed on CD21, so I told the OB that my LMP was a week later, otherwise my EDD would have been Aug. 30 instead of Sept. 6 like it is.

[BlackSheepPDX]

I'm not a charter, so I can't answer your question in the detail you're asking, but here's some more data that speaks to your situation. I'm a 30-31 day cycle. I didn't have an early US last time so my EDD was LMP based. I went into labor 1w5d after "40 weeks." This time I had to have an early US because we were concerned about an ectopic, and they wound up dating me, hey guess what....1w4d later than LMP would have predicted. I strongly suspect this birth may actually happen "on time" based on this more accurate date!