how long do you bleed after D&C?

What is the normal amount of time you bleed after a D&C? I had one 4 weeks ago and I'm still bleeding. Not a lot, mostly spotting but I'm so annoyed it won't go away! I'm wondering if I need to call my doctor. I had my first D&C in February and I think I bled for maybe a week at the most. But that one was to remove tissue left behind from when I had to deliver my first baby that passed, so maybe that was different? Thanks for any input!