No way RIGHTTTT !!????

So The last day of my period was Nov.29 (before this period I took plan b) I didn’t really know when I ovulated since I was on vacation I didn’t really take chart of that . Anywayssss I had sex with my boyfriend on Dec .21 I’m not trying to get pregnant right now so we use condoms and the condom slipped off while we were having sex and it was stuck in me. !!!!! When we realized he pulled out and finished outside (nowhere near me ) when we pulled out the condom their was like pre cum inside the condom. I’m late on my period now OBVIOUSLY! I get cramps I get acne I have sore boobs BUT NO PERIOD !!! i also tested but it was negative.