SO Nervous

My boyfriend and I had anal sex for the first time a few weeks ago. He came on my back. No condom. We had it again the next night but before the anal sex, we had sex with no condom. Just a few thrusts. Nothing too major. But still no condom. He came inside my butt during anal sex but I'm worried could it have dripped into my vagina? And how about if he was to produce pre cum? Worried as I am, I took plan B the next morning. But I think it's been about a month and I should be getting my period right now but I haven't yet. I'm started to become paranoid. My nipples are a little swollen. And I keep looking in the mirror. PLEASE HELP ME.