Pregnancy scare advice

Hi everyone I need some advice or I guess a reality check. I had sex Sunday early like 3 AM and that was the first time I’ve had sex in 8 months since I took a celibacy break due to some past trauma. Im currently taking oral birth control tri cyclen or wherever it’s called but not too great about taking it on time and missed two doses. He never came in me, he did on my stomach. I know pull out method Is far from a great birth control option. I ended up taking plan B about 18 hours after the encounter. Now I’m freaking out and convinced I’m pregnant. I’m a hypochondriac on top of the fact I just went through some sexual trauma so I’m very much over thinking this. So What are the odds I’m pregnant? And how can I deal with this insanity anxiety? Anything helps thank you!