i agree with April2, that can definitely affect your period. also if your stressed more than usual, i remember that when i was a teenager and was stressed over something i wouldnt start my period for several days and up to two weeks past when i should have. but definitely eat more food from what you said it sounds like your not eating that much. if you just dont have an appetite for more food, try eating 5 small meals a day instead.
It sounds to me like you're not eating enough. That can affect your period. You should eat three meals a day plus small snacks to keep your blood sugar level. They don't have to be big meals but you do want to eat something in the morning, even if it's just toast. Your body has already been fasting all night and then to skip breakfast means you are going several hours longer without eating. This is unhealthy and will make you feel tired and foggy. Try having a smoootie for breakfast, a salad or soup for lunch and then a healthy dinner and see if you don't feel better and your periods adjust back to normal.
Take care!
April
lol relax its normal! most women's periods never regulate, i know many women in that situation and i knwo just how annoying it is - i used to be one of them. If you want to be more regular i'd see a GP and go on the pill, that way there's no worries about when its due :)
if you never had sex so its impossible for you to be pregnant :) If I was in your place ( aperantlly I cant Iam a male :) I would go to a doctor and ask about it. I am sure its not something serious my girl freind has it al lthe time.