The night before I started my period I began feeling weak and feverish, chills everything. That same night at 3 am I started having cramps so I went to the toilet, I didn t have to poop but the cramps got so bad I was screaming. Then I threw up everywhere and the cramps continued to get worse. I could barely breathe, I m not pregnant nor have I ever been, but it felt like I was giving birth. The worst of it subsided after about half an hour, but the painful cramps continued, I still have them. The strange thing is the weakness. I feel weak everywhere, but especially my fingertips, legs and back. I m 18 years old. I also believe I may be infertile because I ve been having sex nearly every night for the past year and a half ( with the same man, of course ). I think an ultrasound would be a good idea..