Birth control bleeding

I got the depo shot when I was 18 and had it for a year and didnt get my period once..I got off of it and decided to go back on it again cause I had very irregular periods. I'm 23 and I got it August 3rd a week after I had my period and I've been bleeding since September 1st not heavy like my period but light to medium and it looks like its not stopping so just wondering if this is normal or not