Could Early Menstruation With Clots Be A Symptom Of STD?

HI, i am 19 years and on the pill, I am 5 days early for my peiorid whitch is very unusaual for me(i think it may be my period although not very heavy), i also had a very large blood clot. I recently got forced into having unprotected sex whilst on holaday, could this be an std?