Just curious if this makes any sense... Feel free to skip below the line for the main point of this post.
A bit about me...
I had a natural m/c around 10.5 weeks, though I was expecting it, as it had been a missed m/c and baby stopped developing in the 6-7 week range. I decided to go ahead and TTC in the cycle immediately following the m/c, before my first "real" AF.
Now, I never did have an HCG blood test, as it was all a bit moot (I wasn't even supposed to see my MWs for the first time until 11 weeks and I never needed a D&C, so nobody bothered). However, I took some HPTs after I clearly passed the sac, etc., and saw the line get a bit lighter over a few days, then, about 1.5 weeks ago, well before I ovulated, I took a HPT and got a VERY clear BFN.
So, I have no idea what my exact HCG was at any point, including now, but I can guess that, if not 0, then 1.5 weeks ago, probably below 15 or so, and almost certainly below 25. (My HPT of choice officially detects at 25+, but in trials, detects more like 10-15+.)
Here's my situation with this cycle...
I suspect low progesterone, and my MW and I worked out a "deal" wherein I didn't start progesterone at 3 dpo because I might not be pregnant and we don't want to "mess with things" too much without confirmed low progesterone. I am 6 dpo, and having her give me a blood test tomorrow (7 dpo, or "CD21") as per the usual progesterone testing protocol. Our plan is to start me on progesterone IF mine is low AND I turn up pregnant (ASAP after I find out I am pregnant). I will probably know something about my progesterone by 8 or 9 dpo in any event.
Normally, and particularly given my heightened emotional state, I wouldn't POAS until at least 10 dpo, so as not to get disheartened unnecessarily. However, see above-- if I do have low progesterone AND turn up pregnant, I want to start that progesterone supplementation ASAP! So finding out if I'm pregnant becomes a bit more urgent.
I'm trying to find a balance, but I am admittedly antsy and wondering if I should go ahead and test tomorrow-- 7 dpo (boy, could I overthink this any more!??! )
Oh, and FWIW, I started testing at 7 dpo with my first (it was my first time TTC!) and got my first BFP at 12 dpo, so not particularly early.
Of course I know it's possible, but rare, to get a BFN at 7 dpo. But what I'm wondering is, if you have "some" HCG in your system from a previous pregnancy, would it make sense that you might get a true BFP earlier for the next one? (Of course, you'd have to rule out the fact that a light BFP was exclusively a result of the previous pregnancy, but I feel I have done that.) I guess I'm thinking of a scenario where, say, my HPT detects at 15. Say my HCG is or would be at 8 (if we were only looking at what was being produced by the "old" pregnancy), so I get a BFN. But then my new embryo implants and I can test positive when that embryo is only producing an HCG level of 7 (7 "new" +8 "old," for a total of 15) instead of having to produce a whole 15 on its own (say, a day or two later).
Make any sense? Anyone have any experience with this? Thanks!