Chances of me being pregnant...?

Well im 17 and I lost my virginity 2 weeks ago. He used a condom AND I stopped him before he could "finish" due to the fact that I was scared and it kinda hurt. Annyywaayyss, I am supposed to be getting my period this week but it still hasnt come :( ive been scaring myself soo bad because it hasnt and I read early pregnancy symptoms and it says tenderness? And I have that bad right now D: but they also get tender every month before my period? So I dont know? :( im just stressing about it . What are the chances that I could be pregnant??