Im having a fever before my period this past few moths. also have paint in lower abdomen and back hips. but when my period start it will stop my fever?

Specialist: If you are having significant fevers along with abdominal and back pain around period time, I feel it's best to consult a gynecologist for evaluation and if deemed advisable by him/her, see an infectious disease specialist. However if it's a low grade fever and some perimenstrual pelvic congestion, there is probably no serious pathology present but have a gyn exam nevertheless to be sure.