Blakesmummy - I had my first scan (an external one too) right on 5 weeks because we thought it would be ectopic. They told me I wouldn't see much and only look for where the sac is located (ie if it's in the tubes or in the uterus).

All I saw was the gestational sac in my uterus and that was it, no yolk, no pole, nothing else. So, try not to worry too much about it!

I had a follow up scan at 8 weeks where I could see a blob and hear a heartbeat.

PS. I always sneak a peak at the reports too, can't resist