period almost a week late

Okay I'm not really worried because I haven't been sexually active in over a month. The last time I had my period and got off it I had sex BUT I wouldn't really even call it having sex. It's a long story. I'll make it short. I was at his house. His mom was home. He wanted to have sex we did but we heard his mom and we stopped it was about 5 minutes and I don't think he ever finished. Also condom did not break and ever since that I haven't had sex and now I'm a week late and I'm not worrying bc I know that will make it worse but idk why I'm almost a week late can someone help me and tell me why. I looked up why I'm late and it says too much excersise or sleep schedule changing. And since it's school and I'm on the soccer team I practice everyday and I go to sleep early now. Help?