So a day after my period me and my s/o had sex for about 10 seconds unprotected. the next day i took a plan b. there was no precum he didn’t get close to even finishing. and if there was precum there wasn’t sperm in it because sperm in precum is from previous ejaculations and he didn’t for a while before that day we had sex. about a week or two later i bled for two days a reddish brown what could it be?