Pregnant? help!

I had sex on the 6th of August, which according to two of my period apps was the day I ovulated. We didn't use protection and I stopped taking birth contort in May. I'm not sure if he came inside me, we were both a little tipsy. On the 14th I started to have what I thought was my period. My periods are five days long and heavy enough to sleep with a towel under me, and to use a pad and a tampon. This bleeding lasted three days and was way to light. I checked my apps and this bleeding happened 4 days before my next period was do. I tested when I was 2 days late and again when I was 6 days late, and both came back negative. I'm now 14 days late and have a coppery taste in my mouth, I'm nauseous, exhausted, and very emotional. My next period isn't due til the 16th, should  I test again or wait to see if it comes? Could I be pregnant or is this some freak thing?