Can somebody help me date this and explain why.

Background:

Mc mid Nov. Bleeding started 18th and ended on 28th.

I had a almost positive ovulation test in the 7th which was back pale on the 8th and didn't get another dark test so assuming ovulation was around then.

Midwife has said for her notes she will date from first positive test on the 15th Dec. I do have an appointment at the hospital next week but I'm not really sure if it's a scan or just bloods etc I'll find out the date before.