periods!!!!!!

okay this is going to kind of be long, but i just have no one to talk to about this kind of stuff, so, i got my first period when i was about 11, i’m 17 now, and for the past year or two, my periods have been super irregular, for example, i’ve had only 2 periods since april. one in the end of july and right now, but they are super super heavy and it hurts go walk and stand straight when i get them, they also last for about 8-9 days. should i be concerned /: