3dpo with tiny brown discharge

Hi, i am currently at 3dpo, confirmed with ovulation test kit. Got a positive opk from tues to thurs morning , and neg on thurs evening. Today i had sex with my husband, maybe it got a little rough, a few hours, i mean 7hours later, i check and saw that i have got alot alot of creamy cm plus a tiny speck of brown discharge. Not sure if it has got to do with the sex, will it affect my chance of getting pregnant?

Ps: i had my last bd session on wednesday 2am and second last on monday night. And my husband did not come in me today. If this info helps...

Psps: i did not wipe it, it was on my underwear. Secretly hoping its IB but i know IB is not this early. Just worried if having sex in the tww window will affect any chance of pregnancy. Have been ttcing since may..