D &C related. Bleeding. anything wrong.

Hello!! I had missed abortion and Doctor had done D&C small surgery on 10th December 2018. On 11th December 2018, I had discharged. On that paper - it is written 2weeks rest, normal diet, some medicine etc. As per doctor prescribed- I had small to medium quantity bleeding with small cramps during 8 days after D&C. One day i was feeling too much  cramping then doctor advised me to take Drotin - M --> 3days & Every day 2 tablets after meal .  Now 10 days is over. There is no bleeding. But problem is ---> I  am feeling asmall cramping from vulva, lower abdominal, lower back. But the pain isn't staying during a long time. It is staying 1minute. After that i am feeling okay. My question is - > Why this cramping is feeling after stopped bleeding. Anything wrong.