My last period only lasted 3 days and it was a few days early 2 I've not ad my period this month yet. Also after that last period I ad a few days later I ad the depo injection. Could I be pregnant.

Did you have a pregnancy test done before the injection?
You may have already been pregnant, but most likely it was just your period that was a bit off.

Being on the depo can effect your periods. It is not unusual to have more bleeding at first or periods to minimize or be skipped altogether.

To ease your mind, try a pregnancy test. The depo won't effect the results.