what are the chances that I could be pregnant?

So, I'm on birth control. I take it every night before I go to bed. My boyfriend and I had unprotected sex on day 8 of my cycle, I'm currently on day 16, but I'm having all these symptoms; breast tenderness, nausea, headaches, my bra is getting tight, acne on my cheeks (not normal for me). Just curious if I should bother with a test or chalk it up to a cocktail of different things contributing to these symptoms.