i had sex with my gf 6-7 times withoud condom but we are loyal o each other we didn't had sex with any other boy or girl. we were sexually active 2 months ago but not now. Few days back i saw some spots on the bottom of my penis they are white in colour and look harmless. and colour of my penis from inside is getting dark red. i am worried that because i don't know whether i am having an std or not because i am only 17 years old. should i go to a doctor?