What do I do

How old are you? Sometimes when you're younger it takes a couple years to get everything straightened out. You can see your doctor and see if anything's wrong, usually nothing is, having periods that aren't normal are pretty common. Birth control will usually fix it, and give you less periods. I have the same problem, but I just sort of deal with it.

P.S. This might be usful to everyone else too (and me in case I'm wrong), what do you mean by "normal". Do you mean like the schedule? Or something else?

A little more information is helpful in order to give an adequate reply.
Are you bleeding too often,not often enough?
Are you on birth control?
What is your age?
Is it possible you could be pregnant?