I've been having mood swings...but I'm only 14?

[Sha]

I've been really angry lately maybe in the past few months. It's usually on the weekends, and if someone talks to me I answer back and get angry and annoyed. And sometimes, hardly ever I just cry or something over something little. It's usually with my parents or my sister. I get enough sleep, especially on the weekends, and I haven't gone off at anyone at school. I don't know what to do but mum and dad are starting to get really angry at me, but I can't help it. Is there something wrong with me? Should I see a doctor or something? I really don't know what to do. At first I kept telling myself that my parents are just annoying, but I don't know. It's not just during my time of month, and my period started at the beginning of last term. Could it have something to do with that?