Weird things going on? opinions pls

so my period was late for about five days. on the third or fourth day of it being late i took 4 different types of pregnancy tests ( yes i know it's a lot i was very stressed out) then all of a sudden, blood came and i wasn't as stressed. but then this period was lighter than normal but i had cramps so bad i couldn't move. for four days it was just light but enough to fill up a regular tampon (i usually use supers) . sometimes clumps would come out but it wasn't dripping or anything. the fifth day in the morning i didn't see any blood anymore so i decided to not put anything on. but when i was at the gym i felt like wetness and i went to the bathroom and holy shit it was a bloodbath that im usually used to. clumps and dripping (tmi im sorry but you guys get the point) next day it stopped. do you guys think i should visit a gynecologist? i'm 17 and maybe my body is still developing and my cycle is changing?