Lovisa it could be that your body O'd later than normal (mine did this). I geared up to O, even got a positive OPK and then didn't O until almost a week and a half later (got another positive OPK). It could also be that your pg and your levels aren't quite high enough yet due to later implantation. I do suggest calling your doctor and getting a BT to see if you did O as well as if your pg.