Vicky
an internal scan is easy -nothing to worry about. They protect your modesty and the probe is thinish (nothing like the horrid metal speculum). Your don't have to have a full bladder either. I would request one for peace of mind.

I didn't get m/s or many symptoms really till after 7 weeks and I am pregnant with twins.

Maggie your HCG levels sound fine and not everyone gets triedness or nausea till a bit later or lucky ones not at all. Ask your Dr for a dating /heartbeat scan too if you are worried.

I agree with Sarah -it so normal to worry and usually it is okay - goodluck ladies. Keep us posted