Hi there, I really don't think an internal u/s is a big deal - I mean you've had bigger things inside of you to fall pg LOL. Having had fertility investigations and treatments, I am a veteran of the internal u/s and they don't hurt at all, plus you're covered by a sheet so not even that undignified.

I had an u/s when I was 6w0d and was expecting it to be an internal, but like Ambah the sonographer had no trouble finding the heartbeat and other stuff with an external.