Please help, don't know if i have an STD!!

Well I am a 17 year old male, and i have only had a handfull of sexual partners, but have used condoms with all but my most recent. She is on birth control and told me it was ok. Well just the other day before i was leaving for a few days we had unprotected sex. Well the next day i woke up with a strange sore on the end of my penis head, and three small bumps on one side of my penis. I also have a slight burning sensation just as i begin to urinate, but then goes away. Please help.