Pregnant?

Hi, I'm 16 and I'm not sure if I'm pregnant. My boyfriend and I had sex the day before and the day of my ovulation day a few weeks ago, and now I am late for my period. I'm not sure when to take a test. I've been feeling dizzy lately, my boobs have been very swollen, and I've had extremely frequent urination. I don't know if these are signs. Does anyone who has had a baby, or is currently expecting have any tips for me, and can tell me if those are signs? Thanks a lot.