Sarah's right - once you've ov'd AF always arrives the same number of days afterwards unless you've conceived.
I'd say not normally but there could be a medical problem if you don't get AF. I once didn't have a period for nearly a year (definitely not pregnant as I'd been single a couple of years and I'm usually quite regular) the doctor just gave me the morning after pill, he said it would just kick off the period again, it did but he never told me why they stopped. Might be worth seeing your doctors if it goes on too long Of course I could be completely wrong as I've no idea if I ov'd that first month or not.
