Talk to Gynecologist on Missed Miscarriage- No Period After D&c

Hi! I was 12 weeks pregnant when I went for the routine scan and there I was told that the fetus had stopped developing at 8 weeks and had no heartbeat. I was told that it’s a silent miscarriage/ missed miscarriage and I’d be needing a d&c to get it removed. I was booked in for the d&c the very next day and had it removed all went fine. After the d&c I djust had spotting for a 3 days and after than nothing and a week later just some brownish discharge for 2 days. Ever since that I’ve not had my first period post d&c. And I’m worried sick. It’s been 9 weeks and nothing. On 14th of december I had very bad pain cramping like and it would hurt when I went to the toilet. It lasted for 2 days it was coming and going. I went to my dr and she reffered me a beta hcg quant test and the result was negative with my hcg level on 5. I’m so tensed. What could it be? Please help!