So about 22 days ago, my bf and I decided to try anal sex for the first time. He missed and touched my vaginal opening a few times, only a few seconds each time. We didn't use protection but he didn't ejaculate at all. He says that the most would've been pre-ejaculate. He didn't ejaculate at all that day and says that he pissed before we started, which I hope means that there couldn't have been sperm in his pre-ejaculate. Till now, I haven't felt any sensitive nipples, no food cravings/aversions, no spotting (implantation bleeding), no new bathroom routines or anything. The only things I have felt is a mild upper back pain, slight headache (lasted 10 mins), slight moodswings (but its normal for me) and an occasional minor cramp mid-stomach. It's been about 36 days since my last period, but I have an irregular cycle. However, I still have not felt any period symptoms that I usually feel... Could I be pregnant..? Thanks in advance.