Please help I need advice

I am completely falling apart. I'm a week late for my period and my boyfriend may be leaving me. I fell in love with a boy. He preached how to make relationships last. After almost two months he is trying to leave. I hurt him by hiding my feelings for him when I am down and I posted a photo without a shirt (there was a sticker over my boob's, you couldn't tell they were showing in the original photo). I know I hurt him but I don't wanna lose him! He's has begun to give up on me. I love him and don't want him to leave. He is my Everything, My rock, my best friend! On top of all this, I have never had a late period in my life! Me and him have been irresponsible and having sex without a condom, and now I am worried. My best friend is staying positive and tells me it's probably because I've been crying so much over my boyfriend. I have no idea what to do. I cannot tell anyone in my family until I know for sure because they would shun me and hate him. How do I save our relationship! What do I do over all!