Eating problem :(

So i started my period yesterday and ever since i did i haven't had an appetite. That morning i tried eating an apple and i couldn't even eat the whole thing! Then later that day i had some yogurt tried to eat it and for some reason i couldn't stop gagging, the only thing i could eat were a few tortilla chips. Then today i havent eaten anything untill right now. Im sitting here looking at this pizza and honestly i dont want to eat it. Im not sure whats wrong with me to be honest.