help?????

hi. i don’t know if this is the right place to post this but i don’t know where else to go or who else to ask.

my bf and i did the dirty earlier today. the condom didn’t come completely off, but half way. i saw what might’ve been semen on him (or lube, or my body juices, idk what to call it man, i’m tired and anxious) and bought a plan B just in case. now, i got my period a few hours after we bought the plan B.

that being said: i don’t know if semen got in me. i don’t know if i should take the plan B. i don’t know what would happen if i took the plan b on my period and google isn’t rlly saying. i’ve never taken one before. i don’t know what to do. pls help. thank you in advance.