Could I be pregnant?? PLEASE READ!

Lisa
Ok the first day of my last period was August 12th. I still have 13 (soon 12 since it's 10pm) til my next period. We had unprotected sex multiple times and I am not on birth control (pull out method used) I am taking hydroxycut and usually it makes me wired and jittery that's it. But lately when I take it I'm EXHAUSTED shortly after, I feel extremely dizzy even hours after when I stand up, and some random surges of slight nausea. they say the dizziness is a side effect along with the nausea sometimes. But it hasn't been effecting me like that til recently.  Any opinions?