In addition to the tests above (which were all done by bloodwork), my husband also had bloodwork. They tested us for "genetic compatibility". I had bloodwork to test for blood clotting disorders. I also had two tests (the names are eluding me right now) which were a bit more invasive. One included injecting dye into my uterus under x ray to get a good look at what was happening there. They were looking for things like scar tissue, etc. I also had a small camera inserted vaginally which once again was to see the inside of the uterus. Both were a bit uncomfortable, but not painful.
I had a few ultrasounds. I also was checked for things like liver and kidney disfunction, and a general overall physical.
Nothing was upsetting or painful. It was just time consuming. In my particular case, nothing really turned up, but I was 40 when they did it, so we really did suspect it was just older eggs. Oh, and they did test fetal tissue with at least 3 of my losses.
All the best to you, and I wish you well. But if they do not turn up anything, please do know that you still have an excellent chance of having a baby. I had a perfectly healthy baby boy after my 5th loss. So stay hopeful ok?. Let us know how it goes.
They probably will check your fsh, progesterone, estradol, thyroid, to start with. Sometimes an ultrasound to check for uterine abnormalities and your lining. Good luck