CW Discussion of Fertility / Pregnancy / PIV sex: How do you guys track you fertility cycle after your period stops?

So I've been on (low dose) T four months now (yay). I also recently (almost two weeks ago) had PIV sex for the first time. We did use protection, but not before the head of his penis accidentally slipped inside me.. and then not so accidentally a few more times as he pondered aloud whether or not to put a rubber on. I insisted, so he did before proceeding further, but later on I realised later that some precum might've come in contact with my vulva. (He did apologise later for that, and said he "knew what he was doing, but should've made more of an effort to put (me) at ease for my first time").

Most people say getting pregnant from precum is pretty rare, but not impossible. I know friends of friends who've had it happen. I tried not to overthink it, but at this point I'm a few days late and the panic is rising. Not sure if it's because the T is doing its thing OR if it's because it's just late from stress or whatever... OR because I'm pregnant.

I'm taking a pregnancy test later tonight.. and then tomorrow.. and next week to be extra sure. Ultimately whether I'm actually pregnant or not I'll be okay one way or another, but it got me thinking.. since T doesn't completely stop your ability to get pregnant, how do guys without periods make sure they're not pregnant after having PIV sex?