Wow, I saw the community midwives *way* before 27 weeks!
The thing about my pregnancy is that it started in the US, we moved to the UK, then moved back to the US all during the course of it. So I had 4,5,6 and 7 week scans in the US (we had some problems conceiving, so the RE I was working with did scans each week before releasing me to general OB care at 7 weeks), had an initial scan at 9-10 weeks with the NHS which was exactly the same as in the US -- my green notes detail the heartbeat data, so we definitely heard it). Then I went home to the US for a 12-week checkup, then back to the UK. At 13-14 weeks I was walking around London with DH and a friend when I discovered some bleeding and was rushed to the hospital, where a wonderful, absolutely god-sent midwife dragged the nearest ultrasound tech up to the OB ward for me, and again we heard the heartbeat and verified that the little one was fine. Then I had my 20-week scan in the UK, and that was business as usual -- we had the 2D and 3D scan, as well as hearing the heartbeat. Again, it's all in my green notes. My visits to the midwives -- 3 in total before I went home -- also give HB data.
There was no distinguishable difference between the scans I got in the UK and the scans I got in the US, so I was quite surprised to read that hearing the heartbeat wasn't standard!