Please give me help!

Ok I need help, I've been on the pill regularly and I never miss one
I had sex a while ago now before an opp and I have had two periods 
However I spent a week feeling nauseas straight after my period then that stopped and I just feel bloated 
I took four pregnancy tests all at different times and all came back negative and I also started getting white discharge a week after my period
What is wrong with me ?? What could it be ??