late?

I have never had unprotected sex, or sex at all for that matter. My period is now five days late, I'm normally kind of irregular but now I'm curious. Here's what's happened in my life recently: I'm in the second quarter at school and my French class is very hard on me. My teachers is mean and I'm not doing very well, at the end of October my swim season ended so I stopped working out and now my diet isn't the best, I also don't drink a lot of water. I'm slowly making my diet better, but could these things be affecting my cycle?