My cycle has always been regular about 29-30 days, and getting period 14 days after positive opk like clockwork.

I have started taking prenatal vitamins every day the last 2-3 months and noticed my last 2 cycles are way off. This last cycle was 20 days long with period coming 5 days after positive opk. The cycle before that was 26 days long with period coming 8 days after positive opk.

I am trying to think why all of a sudden my cycles are off and the only thing I can think of is starting the Actif Organics prenatal vitamin. I am on no other medications.

Anyone have experience with this? Thanks!