What Causes Strange Vaginal Discharge?

Small clots of strange looking stuff have been coming out of my vagina the past two days. Im not even on my period, and I'm 17 days too early. I don't know what's going on. My boyfriend and I had sex 5 months ago, but we have been practicing oral. We both came clean on both our STD tests last year. Scary thing about this "discharge" is that it almost looks like chunks. Please help!