What Causes Light Periods And Continuous Bleeding?

HI i m 24yrs old, 51- weight . Have gone through complete intercourse first time around (20 days back). I am facing blood from urinary area, have gone through pregnancy & urine test as well as culture test. pregnancy test is negative, Urine test report is as follows: epithelial cells - 4-6 /hpf, pus cells - 3-4 / hpf, RBCs - 10 - 15/ hpf, crystals - absent, others - nil.
Urine culture shows no growth after 48 hrs. But still i feel blood from urine part. My menstrual cycle was not regular this time. very small amount of bleeding was there. can u please tell me what is the actual problem and why blood is coming from that area?