Pain after miscarriage
is quit normal for sometime. But since it is nearly 6 weeks ago and you still have pain it should be investigated thoroughly.
On a remote possibility it is nothing of psychological effect on previous misconception.
is done after miscarriage to see for remains present in uterus
Sometimes USG cant show any remains due to the thickness etc.
In such case it is better to do a blood HCG
to identify decreasing trend so that to ensure complete removal of the remains.
So your Gync may suggest a D&C immediately for you if she suspects any remains of previous conception since it may cause life threatening complications.