I'm suppossed to start my period on two weeks, and i have this dark brown discharge on my panties and had unprotected sex a few days ago. what is this?

Change in hormone...: ...levels is the most likely cause. There are normal fluctuations in hormones that can cause spotting (minor vaginal bleeding) between periods. Since you've had unprotected sex, you should check a pregnancy test in about 7 days or if your next period is late. It's best to have unprotected sex ONLY if you're trying to get pregnant. Best wishes. Dr. Anne