I think i have a pelvic infection. been feeling sick, unusual discharge and bleeding with lower back pain?

See a doc for PID: Yes- this could well be "Pelvic Inflammatory Disease" or PID. You describe typical symptoms -and unprotected sexual activity is thee risk factor. Do you know the health status of your partner(s)? You really NEED to get this checked, because there can be complications - including worsening of the illness and the health of your womb/female organs. Hopefully going forward u can use safe sex practices