Am I pregnant?

Lately, the past few days I've been having weird things going on with me.

I'm on birth control and the first time my boyfriend ejaculated inside me was a little over 2 weeks ago.

I've been having period symptoms, but no bleeding, decreased sex drive, sensitivity during sex that I didn't have before all this, fatigue, cramps, nausea, stomach pains (in the actual stomach organ) that feel like acid reflux or heart burn, soft stool, headaches, lower back pain...

I took a pregnancy test today and at first I could have sworn I saw a faint second line, but as it cleared up it disappeared.. I don't know if I'm really pregnant or not, but my boyfriend was a field medic and he thinks I really could be and I'm quite frightened...