What Causes Dizziness, Increased Appetite And Delay In Periods?

hi can u help me? i had un prected sex in decemer and a few weeks later, i noticed that felt like i would passout every day, a few times during the day but i didnt i just fet dizzy alot, then my appite picked up very much and my period is 4 days late now...can i be pregnant but i dont have any other symptoms accept i catch hot flashes through out the night tar