Am I Pregnant? I've even gained weight!

Well, a few months ago, like close to the end of January (25/26), I had protected sex. A few weeks after that, I started getting some pregnancy symptoms like bloating, food aversions/cravings, sore breasts, headaches, cramping, fatigue, back pain, nausea, constipation, etc.. It's kinda hard to keep track of my period because I am irregular but I was always getting it every month. The first two months in, my flow was heavy so i didn't think that i was pregnant, but now my flow is real light and it confuses me. It's like I barely get it anymore. I can almost never tell when it comes on. But anyways, as the months went by, I really started thinking that I was because I felt like this fluttering feeling in my stomach like something was in there. And on top of that, my ankles don't look swollen but they've been hurting me ALOT lately. My headaches have gotten worse and I'm always feeling so tired. I've even gained weight which has really had me concerned. And today, for instance, I've had terrible cramping in my back and it was very persistent and painful. My back has also been a real pain lately. It's always hurting me. But just in case if i am pregnant, I already am looking into adoption because i am too young to be raising a child on my own. I don't believe that I'm financially or physically ready.

Oh And Btw, I'm only 15 and I know, its too young...