Is this normal? (girls only please)?

I just got my period for the first tome EVER in February 2010,like the first week.Then I got it a week after the first one ended. BUT THAT'S IT! I'm starting to worry. I went to the school nurse yesterday because I had a stomach-ache and diarrhea. She said it was most likely PMS so she gave me a hot pack and it helped. Alright my question is is this normal? And is this PMS? And if it is PMS is it normal for my inner legs, , and crotch ares to be abnormally itchy? (and if it makes a difference at all- I am a 14 year old gymnast)