miscarriage in July, still no period

Brittany • Mommy to a beautiful boy 6/8/17, Pregnant with baby girl due 9/11/19
I had a miscarriage at 7 weeks on July 18, and it happened naturally at home a few hours after the doctor had confirmed with a sonogram, and I bled for about a week after that. So here I am, almost 7 weeks later, and still no period. I have had brown spotting for about a week, but no blood. I called the doctor, and they said if I don't start it by Monday to call back and they will make me go for blood work to confirm I am not pregnant( which is annoying because I know I am not) and then take medicine to give me my period. Anyone else experience this?