I'm 17 almost 18. For the past about 2 weeks now been cramping off and on at first it was a sharp pain that lasted about 2 or 3 days. I've been naseous and tired all the time and hungry like crazy and peeing a lot more and I just feel out of breath even just while talking. And I just have a feeling I'm pregnant. My last period was December 18 and lasted about 3 days. And now it's due in 2 days. And usually I don't cramp until a day or two before my period. Any advice or input?