Get drunk and have sex

My boyfriend and I are both 21, and we've been having unprotected sex for 4 month and nothing has happened. My period stopping around March and it hasn't been back. Took tests and they've all been negative. My period also stopped in October till April due to birth control messing up my system. I'm tired of wasting tests and feeling like at my age it shouldn't be that hard for it to happen. Idk how to let it go