never had sex Ed so I'm unsure

Hey my name is Maya and I'm 15. I had sex a lot with my boyfriend and he always pulls out but like sometimes he goes back in after he finishes. My period is 9 days late and I'm worried something is wrong with me but idk what. I took a test 3 days ago and it said I'm not pregnant or anything. I just been having this light tan discharge for 10 days now. it doesn't stink and I'm not itchy and nothing is weird about it. it started out very watery but now it's creamy like... Help!