Minor condom mishap, should I get Plan B?

This evening I had sex with a guy and we used a condom. He finished, and attempted to slide out of me but didn't grip the base of the condom. Part of it got stuck in me and he had to pull it out. I should clarify, 3/4 of the condom was still in me, while the ring portion was outside of me. I wish he would have warned me too so I could have unclenched or atleast helped, lmao. When I went to the bathroom to pee, I noticed a bit of semen on my butt cheeks, and another wet substance (which honestly smelled like lube and my own arousal.) I got a bit freaked out. Weird part here, but I stuck a finger inside me a few times to see if there was any semen. I didn't see or smell any, and my hope is that it just kinda dribbled out on my butt cheeks when he pulled the condom out. When I got out of the bathroom I made him inspect the condom for any holes, and he didn't find any/nothing was leaking out (even when squeezed.)

I am not able to be on any birth control due to a blood clotting disorder (I'm on blood thinners for it.) I am also not wanting to get pregnant. I am pretty overweight (over 200lbs) and I know Plan B can be less effective for heavier women.

Based on my situation, I'm curious if I'm just really overthinking this. I hope I am, lol. I just finished my period about 5 days ago, so when would be the best time to take a pregnancy test if needed?