I had a Hystosalpinogram in 2008, I didn't know what to expect, so I guess I expected the worst. But the nurses I had really helped and explained everything. You wear a hospital gown. Then you lie flat(on your back) on a bed, and an x-ray machine is directly above your lower stomach/pelvic area. While you are on your back your legs are in stirups(the lights are dimmed,if that helps).
The doctor then explains you will feel pressure & cramping.The pressure is from the dye that is being inserted with what looks like a turkey baster. It just feels like air filling in your fallopian tubes. This doesn't hurt, it just feels weird & a little uncomfortable, and if your tubes are blocked dr. says this will help open them.
After the dye is inserted the dr. has you tilt your pelvis to right side/left side. Then the x-ray machine takes pictures of your tubes,from all angles.
My cramping didn't start until the end of taking the x-ray pics. It feels like period cramps only more rapid and alittle more intense. The only way I can explain it is if you have ever eaten hot hot salsa(and had to go #2). Kind of like those kind of stomach/pelvic cramps. Sorry so graphic.
The cramps were uncomfortable for several minutes afterwards only. The dr. requires you to lie there for about 15 minutes. Your given a pad and they send you on your way. The cramping gradually goes away after an hour or two. I think the cramping is from the dye naturally expelling something foreign out of you.
I was able to drive myself home. Yes, there is a little discomfort, but it is worth it.

I am now on my first cycle of Clomid this month. This procedure will get you to your next step.
Good Luck & God Bless