I had a miscarriage at 4 weeks. I was rushed to the hospital but the Navy doc said it looked like I could do the natural miscarriage. You HAVE to go back so they can monitor your hcg levels to make sure they go back down to zero. They also make sure you don't get any infections. I am now pregnant again thanks to being monitored.
You should go to a doctor, have an scan to make sure all passes.
I would go to the Dr make sure it passes and no infection