Hello. Thank you for writing to us at healthcaremagic Sexually transmitted disease/ STD s may present with the following signs and/ or symptoms like vaginal discharge, burning on passing urine, sores/ erosion s, warts or growths, swollen glands etc. Bleeding or spotting is unlikely to be due to an STD. It may be related to the Depo injection or some other gynecological problem. I suggest you to visit a gynecologist for a confirmatory diagnosis and appropriate treatment. However, since you are in doubt about fidelity of your boyfriend, therefore, you must get yourself tested/ screened for all STD s like HIV, Syphilis, Gonorrhea, Chlaymdia, Genital Herpes, Warts, Molluscum etc Regards Always practice safe sex with a condom!