Can A Depo-Provera Injection Cause Heavy Bleeding?

Hi, In November I had a baby. At the hospital they gave me a depro shot. Then in January I had the essure procedure done. I refused a second shot of depro because it made me bleed constantly for months. The bleeding finally stopped but started again at random times. For the past month it seems as if everything was back to normal. I Think I got my first period on March 23rd. During the months from Nov-Feb I couldn't tell if I was having a period or not because I bled at random times. Well, now I started spotting yesterday. Enough that I have to wear a panty liner but I think I'll have to switch to a pad because it's bright red and seems to be getting heavier. Is this normal? When will this shot they gave me be out of my system finally? Do i have anything to worry about?