HELP!!!

I'm constantly being paranoid about being pregnant. How can I stop being paranoid every time I have sex?  I had sex the day before my period. I'm on birth control and he used a condom . My period came . But I've heard sperm can live in you for up to 5 days. And I've been having symptoms such as my back hurting , nausea, stomach aches , sore breast , white discharge. Please help I'm really really scared