What Causes Heavy Periods With Continuous Bleeding?

hi i have my period on 5th of this may and last for 10 days as usual then i have it now in 21st of may, it was in the first two days like spotting and then heavy bleeding. could it be related to a big accident i saw it in 23 of may?? i am still bleeding should i go to the doctor?? what can be the reason ? this is the first time that happened with me and i am 29 years old