toward the end of my period I got a uti it went away with cranberry juice I keep drinking cranberry juice but it keeps coming back?

Need an antibiotic. Cranberry juice has been promoted to prevent or treat UTI, and for a while research suggested it helps. However, the most recent research shows clearly that it doesn't work. You need to see a doctor to confirm the diagnosis and get an antibiotic prescription. Also, at your age (20), STDs like gonorrhea and chlamydia can cause similar symptoms as UTI. If you are sexually active, get STD tested.