Should I go to the hospital?!

So May 8 I had a regular 7 day period. Then May 21 I started again for some reason ?! My blood is very red and it goes about Medium/Heavy.  I bled from May 21 to June 3rd. This happend to me in September 2014. I went to the Gynecologist in 2014 and they prescribed me Birth Control to regulate my period. I take the pills. Im also 15? Should I go to the doc ?! Or is there anything you guys should tell me ?! Please help! 🙈 Extremely worried.