They dated my pregnancy by lmp but I know they are off by a week because I just happen to know exactly when I conceived. Funny little story involving a condom that went missing.

But anway, when I'm not on the pill, my cycle is a lot longer than when I am on the pill. Like 35 days, so the doc says I would probably ovulate later than most women with a 28 day cycle. Of course, I had an ovarian tumour that I didn't know about when I conceived so that was likely the cause of my longer cycle. I don't know when I will find out because I'm planning to breasfeed after I give birth so I'm not sure how all that works. Anyway, long story short, if you have a longer cycle, for whatever reason, you may have a later ovulation day.