Congratulations!! If you're 7-8dpo, I make you 3 weeks pregnant. If you know when you ovulated, you can count the day of ovulation as 2 weeks.
I ovulate really late in my cycle (CD 27!!), so all the GPs make me 8 weeks but I know I'm actually just over 6 because I had a positive OPK and that was the only time the BDing fitted in.
They only work on a 28day cycle and a classic ov day of 14 (2 weeks). Us abnormal girlies are a bit different!!
K.xxx