Girls, I have a question. It's been two months since the birth and abo…

Girls, I have a question. It's been two months since the birth and about a month ago I noticed that my uterus started cramping, like during periods but not too much and often. I had a miscarriage, so I made an appointment with a doctor for Friday, but maybe someone has experienced this? Or should I worry? I am breastfeeding the baby.