PREGNANCY?!

Okay so I've been on the pill for almost 4 months and my periods have still been irregular (like super long and I had a double in May). I was suppose to get my period last Monday and I have yet to see any signs of bleeding but I have a lot more white discharge then normal. The last time I had sex was July 24th and I've had these type of pregnancy scares a couple times before. But since I'm now on the pill I'm 10000% more concerned. Why am I not bleeding? I don't know what to do and my mom has no idea of my actions. I don't want to panic and stress myself out cause then my period will take even longer. But what should I do? I'm so lost