Baby measuring a week behind at 7 weeks

I had an early scan today as I was concerned about cramping I have clear mucus discharge with pink blood and pink spotting since Sunday. It always starts in the morning but lessing as the day goes by.

My last menstral period I baby should be 7 weeks 3 days but I was measured today and baby was measuring a week behind at 6 weeks.

No heartbeat was detected so I will have to go back again next week for a follow up appointment to see if baby has grown.

Baby is measuring 3mm at the moment.

I was prescribed progesterone morning and night aswell.

Anyone been through this? Any advice welcome thank you.