Very short cycle!!

Sooooooo boooom….I had a baby in February. I got on the birth control shot in April my life is liter so hectic n I haven’t been active til recently so I never went back for another round because I had also noticed it slowed my milk flow. Anywho I had a period October 24th through the 27th. Then had another full period on November 3rd. The first time I have been active since my son was the 17th. But now I’m having another period again. Has anyone else experienced these short cycles after stopping the depo? Before October I hadn’t had one since he was born.