Hey! So, I know exactly how you feel. I'm 17, well I'll be 18 in December, and I'm having all of those same symptoms right now, although I'm not yet late for my period (it should come in two days, so we'll see). So I know how you feel.
But from the symptoms you described, it certainly sounds like you might be pregnant.

Have you taken a test yet? Since you are late for your period I would suggest going out and buying a hpt and seeing what happens. If it comes out positive then you should go to see your doctor and get a real test done to be sure. If it comes out negative, wait a few days to a week and if you are still having the symptoms, try again.
If you ever need anyone to talk to I'm here.