Possible miscarriage?

Went to my OB the other day because of brownish blood and lower back pain/cramping...

They did an ultrasound and took blood...

My ultrasound showed a sac measuring 5 weeks 3 days... however according to my last period dates I should be 6 weeks 3 days...

They called today and said my Hcg has not rose since they last checked and my progesterone levels have dropped...

Anyone have this happen and didn't have a miscarriage 💔

Feeling heartbroken...