Sick but what happened?

i was in math cl a little over an hour ago and i started to feel nauseous. then it started to come in waves and i got nervous because that's usually what happens to me before i vomit. I got really really dizzy and i thought i was going to p out, i asked to go the nurse. I didn't throw up. My mom came and got me and i feel sooooooo uch better now that i'm home but it's no use going back to school now, plus it would be embarring. I'm really vurious to find out why i felt like that. I didn't eat breakfast but i ate a nutri grain bar and drank some water in my first period cl (math was 2nd) anyone know what might have happened?????? Also i notice that i've been getting frequent stomach aches over the last week, not severe just a little queasy