Am I okay?

So I’m super ocd and I’m on birth control, have been for a couple years. I take it on time and everything and haven’t missed any. I also haven’t had sex for six months.

So lately I’ve had this fear that I can get pregnant from touching sperm on a towel, or drying myself off with a towel that may have had sperm on it and it’s driving me nuts. I know guys don’t do this.

I’m about a week away from my period and I’ve been super sore and have had some very light spotting. I was concerned about implantation bleeding, but my boyfriend is telling me that’s 100% impossible. Any advice?