HELP!!!

Okay so idk if I’m on my period or not. I’m on birth control (for my acne it’s not strong and more for hormones) but on the package it tells you when you should start your period right? Well mine has like a week left, I have two apps and one says I should start it in 5days and the other says in 3 days. But today I went to the bathroom and in my panties there was a brown slimey substance. I went and danced for about an hour and checked again there was nothing in my panties, but when I wiped it was there. I don’t know what it is so please help!!!