My ob/gyn has put me on Prometrium to help regulate my menstrual cycle. My husband and I are trying to concieve our second child. With my first child I was put on prometrium for the first trimester due to low progesterone levels. This month I thought there was a chance I was pregnant and he told me instead of taking it days 16-25 I should remain on it until I know for sure if I am pregnant. I still have not gotten my period, and I am 3 days late. I have been experiencing the "normal" cramping associated with early pregnancy, but have taken a HPT and it is negative. Can prometrium delay me from getting my period? I am afraid to stop taking it just in case I am in fact pregnant. Any help/information would be GREATLY appreciated!