It's really hard to tell unless you take a test. Some times pregnancy symptoms are exactly the same as your period. You can go to a dollar store and buy a cheap test, or go to one of those free clinics. Or you can just wait until you get pay. In the meantime, if you smoke or drink try not to until you know for sure. That's what I would do, just in case. I don't know what you want, but better safe than sorry, no?
Good luck!
it would be nice if some one helped :)