Prenatal Vitamins/Period

My husband and I have been TTC for awhile now.. just Sunday, I started taking prenatal vitamins and on that same day, AF showed up 😩.... Normally my periods are pretty moderate bleeding and for about 5 days.. however, my heaviest day was Sunday only (afternoon ish) and Monday and Tuesday we're very very light - didn't need a panty liner or anything - blood only showed up when I wiped. This cycle has been so weird!

My question.........can prenatal vitamins affect my cycle? Has anyone's been effected? I just saw my OBGYN on Friday so I really don't want to call again.. 🤦