loooong ass period

i got my depo shot for the first time August 2nd, while on the second day of my period. my period in september you was late so i thought i may not get one due to being on the shot. However, I started it (i’m never late, my period’s aaaalways right on time) 10 days later than i should have. Also, my period’s are usually 4ish days long but i have them like, twice a month?? i know that’s not normal but it’s the way mine have been for forever. & it’s been 10 days since i started my period and i’m still on it. I definitely bleed lighter now, but it’s more than just spotting. I guess I’m asking if this is normal? I go back to get my second shot late October so I guess I could just wait until then to ask but I’m sick of bleeding for so long haha.