Can prenatal vitamins cause your menstrual cycle to be late?

So my husband& i are TTC with our first, have been for 9 months now. About 2-3 weeks ago my doctor put me on prenatal vitamins and im currently 4 days late on my cycle.. is this normal?

Also, i took a pregnancy test two days ago, that was negative.

I've had cramping & other period symptoms off and on for like a week now.