Just thought I would add to this as I had the HyCoSy done yesterday, and from reading here it seems like my experiences might be relevant.

The hycosy is done with internal ultrasound rather than x-ray . I have to say it wasnt the most pleasant thing I have done, and it was uncomfortable with period type cramps. However it is over fairly quickly and you know there and then if there are any problems (luckily I was clear). The cramps lasted for about 15 minutes afterwards. I too was advised to take pain rerleif beforehand.

It cost $450 (ish) at Sydney ultrasound for women, so appears to be more expensive than HSG. It has to be completed by a doctor and before ovulation.

Hope this is useful