Is it normal for my period to be lasting ten plus days?

Not normal, but? A ten day flow is not usually normal but doesn't have to be alarming. You don't state how heavy the flow is or any other characteristics or problems. You may have had an an-ovulatory cycle. There may be other reasons. Medications? Illness? Missed pills? If it continues or if there are other concerns or problems, call or see your pcp/gyn and get examined and treated. Pregnancy/miscarriage?
Prolonged period. The average period is around 5 days plus or minus 3 days. Yours is a prolonged one. If this is persistent you may be at risk for anemia. Go get it checked out.