I don't know how old you are or if this is the first time you've had unusual bleeding, however, if this is abnormal for you, call your doctor. Ask to speak to a nurse - tell her / him what's going on and see if they think you need to come in for an exam. If you have irregular periods, you might see if using a birth control pill will help regulate that for you.
As a general rule, if your body is doing something that doesn't feel "normal" for you, you should get it checked out.
