Am I pregnant?

I had my period on the 3-8 had sex the 14 and 15th. Now the last 2 days I've woken up with headaches then it goes to just feeling ligh headed all day. I get nauseas throughout the day and thought of eating makes me sick. I pee so much and have a dull aching pain in my lower stomach like I'm going to start my period. One colander I have says I'm going to start on the 22nd the other one says July 1st. The 22 seems to soon only 2 weeks? Id love a baby but this was just a mistake!!!