Get Insanely Paranoid After Sex, On Diane 35. Feel Tired, Have Headaches, Decreased Appetite. Could I Be Pregnant ?

This is probably going to sound ridiculous but I always get insanely paranoid after sex. I had sex while on my period, using a condom, and I am also on the pill (Diane 35). I recently did get my period when I was supposed to (a few days into the 7 day break) but I have been feeling really tired lately, I haven t had any other signs other than some slight headaches but not often. I am wondering if these are likely just results of my pill and stress? (When I start my pill again it usually makes me nauseous the first few days) I have somewhat of a decreased appetite and really just need my mind to be put at ease... is it really that possible to get pregnant after sex on your period, on the pill, using a condom and not missing your period?