hi K.,
you might want to check and make sure you aren't pregnant. i had an irregular period after becoming pregnant with baby #3. the dr's at the time, went with that being my last regular period, and along with an ultrasound, decided my due date was may 2 (1988). i had him april 20th, and was told he was almost a month over-due!! needless to say, i about died! he had several over-due symptoms(but didn't realize it was things pointed to being over-due), even to my eyes, that i had not seen with the other kids(never over-due with the others). i pointed these things out to a nursery nurse right away, and she says, honey, didn't anyone tell you your baby was over-due?? i said, "WHAT??"!!!! so by the time i had left the hospital, there were a total of 3 nurses, and i forget how many different "over-due characteristics, etc" that they had went by to tell me he was seriously almost a month over-due! i know ultrasounds have changed greatly since then, but i have never trusted one since, in deciding my due date. (i had 2 more after #3)
so anyway, keep in mind that it might be a possibility you might already be pregnant! and best wishes, and best of luck!
C.