I was abit nervous about Internal U/S as I'd never had one, but when I was M/carrying they did a few to see what was going on, they were not at all painful, or anything, basically I didn't really know anything as i was just looking at the screen..
With this preg I had one at what we now know was 2 weeks, but it was to see if M/C had cleaned out everything!!!!

I will not be nervous at all about them again I think in 6 weeks I had 4!!!!

So if your worried don't be they are very gentle & professional about it!