Long period

My period has been on since the 17th its now Nov 27th and my flow has gotten heavier I'm not sure why or when it will slow down , My last period lasted 6 days (normal for me) and that was back in August. I get a period approximately every 3 months or longer and I've never been on birth control nor have I been involved in sexual intercourse .... I'm so confused & scared to see a doctor. Should I be worried?