Talk to Gynecologist on Missed Periods

Asalam o Alaikum. I have history of miscarriage in feb. after that my periods came on time but were prolonged like for 13,15 days for which I took duphaston last time. I took 1 week course my periods came after 3 days that is on 15 and ended on 20. But now I have missed my periods. I took home pregnancy test and beta hcg test both came out negative. I’m 9 days late on my period what could be the reason ? I had always normal cycle before. What should I do next? My age 26 weight 56 no other medical problems.