I had a BFP at three weeks pregnant with my first pregnancy... I just had a feeling I was pg and tested early. That said I've also had scans which have been weird. I have had two scans in two different pregnancies where bubs measured small for dates and I chart, so I know when I conceived. First time this happened I think it was because I was about to lose to baby. I'd never had good hcg readings and I had had bleeding as well. I measured a week small at 7 weeks.

But with this pregnancy I am 15 weeks. I know when I ovulated and at my dating scan at 8 weeks I was proved right - I measured exactly what I thought I should, to the day. But at my 12 week scan I measured 5 days smaller than I should have. Babies grow at different rates. This baby is fine.