you're upperclass but you still dont know to use condoms!!!! go to a clinic and get tested, and hope to god she doesn't inform you that she's pregnant
Also, you are so young dont get caught up in the "OH SEX IS SO COOL" thing... It really isn't worth getting something that could harm you. BUT if you choose to continue having sex PLEASE wear a condom NO MATTER WHAT!!! I don't want to sound like a mom or an old person but honestly there are ppl who get on here who are twice your age still having unprotected sex and catching STDs and damaging their bodies and freaking out because they may have gotten something.
when you do have a partner make sure you both get tested before having unprotected sex.
well given the age it is most unlikely she has HIV but if shes had multiple partners it is possible. Unprotected sex is a risk for chlamydia, gono, Herpes, syphilis and HIV. Try to relax. Talk to your friend, see if she's been tested and if not go get tested see below for the testing time lines. Also, tell your 15 year old friend that unless she wants to have serious issues with her body she needs to start wearing a condom or stop having sex with multiple partners.
Chlamydia & gono- 7 days post
HSV (Herpes) - 3-4 months post
Syphilis- 4-6 weeks post
HIV- 3 months post for a conclusive result but testing 6 weeks post is a good indicator