Extremely heavy period

This is my first period since I decided to go off Birth Control. And I have never had a period this heavy before. Im 27 and I have a 4 yr old daughter and I have been on birth control since she was born. My period started yesterday on time but where as its normally pretty light this time it was so heavy that I had to change my tampon every hour and I got in the shower l, I looked down and there were clots blood coming down as I showered. I guess My question is... Is this because I've been on a birthcontrol that basically stopped my period and its all coming out now (if thats possible) or should I make a doctors appointment???