Thank you for your question, and I am sorry to hear about your symptoms. You should visit with your primary care or obstetrics and gynecology doctor
for further evaluation. Generally speaking, antibiotics will only be useful if your symptoms are caused by a non-viral infection. Although it sounds as though you have been having normal periods, you should be tested for pregnancy. When pregnant, spotting or brown discharge may occur early in the first trimester. Pregnancy aside, brown discharge could also normally occur shortly after periods or mid-cycle during ovulation. Douching and having unprotected sex with multiple partners are risk factors for other infectious causes of discharge (which could be treated by antimicrobial medications). Yeast infections cause intense itching with white "cottage cheese" discharge and pain during intercourse. Bacterial vaginosis causes grayish discharge with a fishy odor, but usually no itching. Trichomoniasis is characterized by greenish/yellowish discharge, often with pain during urination and with intercourse. A simple microscope analysis of the vaginal fluid can usually tease these diagnoses apart. Finally, it is always prudent to be tested for sexually transmitted diseases such as chlamydia, gonorrhea, and HIV, especially when having unprotected intercourse. I hope that the above information is useful, and I would again recommend that you see a physician to discuss your symptoms further.