long post coming: first pregnancy was di di twins. I got a bfp, very clear, at 7dpo (confirmed with opks) Second pregnancy was singletons, again, clear bfp at 10 dpo. fast forward I'm 6 month pp and my period has been back since 8 weeks pp at about 43 day cycles. (was 35-38 before my twins) my last period started October 19th. ran fiveish days. well I'm on CD 55 now. I didn't bother to test till CD 50 because we haven't been making much effort and my cm hasn't been great, but definitely dtd twice in fertile window. the kicker is all my tests are totally blank negatives. I took four frer (from two separate boxes) and three clear blue over a 5 day period. tried morning and night. Nada. I've never missed a period. I've never been this late without being pregnant, and I'm wondering if maybe it's twins again and I've waited too long and am getting bit by the hook effect. It seems I tend to have a pretty high hcg level since I always get clear early bfps. I'm feeling mellow and having heartburn and a tad slowed down in the bowel dept, not at all like I typically am pre period. Thoughts? I'm planning to go for a blood test next Tuesday if I've still seen no sign of AF as I have a condition that needs lots of monitoring in pregnancy. Im mostly wondering if anyone has actual experience with the hook effect? Thanks in advance!