Today is the first day of my period, and i got it like expected. i feel really lightheaded and i threw up. is this normal?

Yes this is normal: I am sorry to hear about your symptoms. But this is to be expected with a menstrual cycle from time to time. If your concern was due to the idea being pregnant, and that pregnant women have morning sickness. You should not be worried. You cannot be pregnant if you had your period. The flux of estrogen and progesterone that happen during a cycle can cause nausea. In a day or so you'll be fine