I had sex without a condom about a week ago (I've been on the pill for about 2 years and have not missed a pill or have been late this month), the guy pulled out but I was still worried so I went and got Plan B. I was just wondering if it messes up your period even though I'm on the pill and the pill regularizes your period. I have read online that girls got their period about a week or two late but I'm assuming that they are not on any sort of birth control? I'm supposed to get my period in about 6 days.