Please any advice? Dates say 6w3d

Loz

So I had some bleeding the night before last, when to my doctors and sent me for a scan. Cervix was closed so they couldn’t tell me why I’d bled but said it was fine as not from the baby.

Then had a scan and the doctor struggled to see the yolk sac but there was a clear fetal pole. Could it be that she just couldn’t find it? Re-scanning in a week. HCG levels have gone up from 5,000 last week to 31,000 yesterday. More bloods tomorrow. Just confused as to why they couldn’t see the yolk sac and she didn’t explain it very well! Any advice much appreciated!