Depo shot

Hannah • 20yrs old trying to find my way
Back in mid February I received my first injection of the Depo shot. The nurse told me I could have some spotting for a while after receiving it. Luckily I had no bleeding or spotting until last Tuesday. The problem is that I am still having mild bleeding 10 days later. My periods usually last about 4 days so this is pretty abnormal. I'm wondering if it's the shot that is causing the long menstral cycle or something else. Any advice would be appreciated. Thanks