Dark vaginal discharge, uti might've lead to kidney infection, vomited yesterday w/severe headache out of the blue on the pill&had unprotected sex. ?

Possible STD, PID?: I'm worried you have an STD, like chlamydia or gonorrhea and maybe pelvic inflammatory disease (PID, fallopian tube infection). Brown vaginal discharge goes along with STD more than UTI, and gonorrhea and chlamydia can cause urinary burning, frequency, etc. like a UTI. Abdominal pain from PID can be confused with kidney infection. Whichever you have, this is serious. See a doctor or clinic ASAP.