..What do you want to know? How about this. Periods are normally anywhere from 23 to 32 days, they can vary from stress or other causes.
You need to go to the doctor and let them run a hormone panel on you. This is something that needs to be checked out as a regular menstrual cycle is reflective of our health in general.
How old are you? Are you overly stressed? Are you on medication for something? Are you very skinny?
I need a lot more information to help you out :) Let me know