I had the same thing (had to have a HCG level drawn to make sure I wasn't pregnant - clinic policy if over 6mm - HA, right!). The nurse practitioner told me I just probably hadn't shed the entire lining yet.
*** Child & current pregnancy mentioned ***
Me - 41 (PCOS), Hubby - 43 (healthy)
7/2013 - Sweet baby girl born (Clomid + TI)
3/2014 - TTC #2, return to RE 7/2014
12/2015: IVF #1 transferred two great looking embryos - BFP!
First ultrasound: TWO beautiful little heartbeats!!
Harmony: negative; level 2: babies look great and are boy/girl!
I had this problem when we were TTC #1. I was told that Vitamin D3 helps as well as POM pomegranate juice. All of my cycles my lining was 7 or less, the month I got pregnant with DD I had been taking vitamin D and started 8oz of POM daily on CD1... my lining was 12! I have no idea if it truly was the vitamins / pom or just a coincidence but I will definitely do the same this time around!
Re: Baseline ultrasound question