DH and I were not sure how long it would take for us to conceive (or if we even could). My maternal family has a long line of exploding reproductive organs (no - seriously) with mom, g-ma, and ggm all getting hysterectomies between the ages of 28 and 39. I was 28 when we got married. DH has a LONG family history of genetic abnormalities AND he'd done two tours in Iraq, playing with all sorts of fun chemicals and toxic waste.
So, when we got pregnant the first time we had unprotected sex (me, with a partially torn meniscus in my knee, but, DH had just gotten back from 7 weeks of training - gingerly pity sex) we were ECSTATIC.
When I was 6 weeks along (beg. Nov '05), I miscarried the baby (definite tissue/clots/etc, and then the doc did blood tests confirming declining HcG levels).
In Feb '07, I went back in, newly pregnant. My periods had come every month, but weren't very "regular" if that makes sense, so, we weren't exactly sure on the time frame. I had no real symptoms, just a feeling (no morning sickness, no tender breasts, no fatigue, and I'd only gained 3lbs - Christmas weight, no doubt).
The doc and nurse both about hit the floor when he examined me...My fundus was at my naval. I was sent across town for an ultrasound b/c he thought I was probably having twins. Baby (just one

) measured 20 weeks, completely healthy. Yep, do the math.
She was born July 1. What we think happened was that I miscarried her twin (which would explain the tissue and declining HcG levels), but she somehow stuck in there. She is our Miracle Baby, and our little One Shot Wonder. We joke that she must have been DH's last healthy sperm.
People are always like, well, how could you NOT know? Like I said, NOTHING indicated pregnancy - I am the symptomless pregnancy woman. And, yes, it does make me paranoid. (And, yes, I had my period throughout my pregnancy - my grandma did, too).
My SIL, btw, is a post-tubal baby (six years post-tubal). My MIL didn't even know she was pregnant until her water prematurely broke early (MIL was in the hospital for weeks before SIL was born at 26 weeks).
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