I need answers!

Leslie
Okay so last month I had sex on the 19 and that same day later on I had my period but my period only lasted 3 days and it was heavy as usual but every month my period last about 7-8 days and I've been peeing a lot I get my period in 7 days and I have milky discharge like I don't know does your period change when you have sex?? No I don't think I'm pregnant! Lol