wtf do I do

okay so I'm very irregular. like I can go 2 months without a period and normally I wouldn't worry but I started having sex with my boyfriend and well I had sex a month ago and then I was admitted in the hospital for brain surgery(health complications) and when I got out I didn't have sex for about 2 weeks and I didn't start in the hospital. so I'm going a little more than a month without a period and I'm not on any kind of birth control. I've had sex multiple times with/without a condom. though he's never cummed inside of me I'm still scared. what do I do? i think stress is causing me to not start but I can't help and think it's pregnancy...