Hi! I am 20yrs old and independent. I am anemic and been taking prenatal vitamins because the regular Iron vitamins make me sick. I haven't taken the prenatal vitamins over a month a few weeks. My boyfriend and I had sex two days after I got off my period and the condom broke and he was certain he came in me. I took Plan B One-Step right after that happened. Will the prenatal vitamins get in the way of Plan B? Please someone help me.