It will take time for your body to get back to normal.
I have micarried in the past and had to have a d&c done aswell, and in my opinion i dont think you may be pregnant, if you have taken tests and gotten a negative result, then chances are that your not. But a miscarriage can lead to abnormal periods after, like for me for example i bled for 6wks after the d&c and then was late on my next period. If your really that worried then you really should go into the doctors to get checked just incase there is something wrong. Good luck