Sounds like your period is just late. It can happen. Did it arrive today?
Your activity would not result in pregnancy, so that isn't a worry. A penis needs to go into the vagina for pregnancy to occur and don't do that unless you have a condom! Use those each and every time.
Periods are late for lots of reasons. Here is a short list that doesn't capture everything but includes being stressed, having a change in your routine (like summer starting), illness, losing or gaining weight, shifts in hormones that happen periodically.
Being late happens to every woman. Even if it isn't your norm, it can happen. And this won't be the last time. Try not to worry especially if there is no chance of pregnancy such as in your situation. Doctors like women to have a period at least once every three months. Some girls are really that irregular that this is their situation. That often warrants going on the pill to regulate your period. But just being 7 days late or a couple of weeks is not to that point. If it keeps happening, then talk to your doctor.