Hi aflight
I am currently waiting for IVF - I'm sure you know what the NHS is like, so we're expecting it to be March/April 2009 before we go, although we may go private after our holiday in September.
I had all the usual tests done - CD21 bloods, CD3 bloods, internals, smears, swabs, and HSG - everything came back normal. DH has had two SA done and he is normal (not so sure about that diagnosis but that's another story

). I was told by a specialist that if I have regular cycles then I ovulate so we have unexplained fertility which is very frustrating. I feel I could cope better if there was a reason for it - but on the other hand it's good to know we are both healthy.
I have a friend who has only had CD21 and CD3 bloods done, and smears, and scans. She hasn't had HSG or anything else done as she has regular cycles and her DH has a very low count. The specialist told them they could run more tests on her but it would be pointless and mean their treatment would be delayed until the tests were done. They have to go for ICSI.
I would go with what FJL said, and make sure everything is clear - possibly ask if there were be any harm in having a HSG done just to be sure.
Hope that helps. Let us know how things go when you talk to the hospital.
x