Cin,
i think you very well could be pregnant.
Heres what I would do in your case. Go to a store and buy 2 pregnancy tests...2 of them. Then tomorrow morning, right when you wake up, get a pregnancy test ready and use it. If it comes out negitive and you still dont get your period, wait a week and try the other pregnancy test.
If you do get your period, then next time you think you may be pregnant, you'll have a pregnancy test ready to go!
Good luck and congrats if you are! :d