seeking advice

Alycea
Does anyone else have the problem I do? Or can give me opinions, I have not had my period in forever and when I do get my period it's so painful and it's a good 2 months long of non stop bleeding , I went to the doctor who prescribed me a medicine to restart my cycle, and after taking that my period was excruciating to the point where my mom wanted to take me to the er , and since then it's been since April since I've had my period and yes me and my fiancé are very sexually active but I've taken tests but all negative ... what should I do ?