So confused am I pregnant or am I not....

AF was supposed to show on 10/21 I took a test and it was negative 2 days later (10/23) still didn't start took another test still negative it is now 10/25 I still haven't started and again another negative test. I am usually pretty accurate on my periods and I feel weirder than normal but don't feel the way I did with my first 2 pregnancys, now I gagged at a poopy diaper which never happens, I'm tired alot, food makes me nauseous. Am I just over thinking this or what? I'm so frustrated because I just want to know.