I lost my baby a few weeks ago at almost 18 weeks, I was induced because the baby had no heartbeat and stopped growing at 13 weeks. They did all the testing automatically for me and this is my first pregnancy and unfortunately loss. I am sorry for your loss...

I had all the bloodtests done after my second m/c, and I am still gratefull that I did. They didn't find anything wrong, but at least I knew that it wasn't from any of the common culprits. There is no risk involved in doing some bloodtests, so why not? They won't be able to do any genetic testing yet, but they can check you for auto immune disorders and your thyroid etc. And going on extra progesterone when you do fall pregnant again won't harm you or your baby. I would suggest that you find a doc that you like, who is willing to walk this path with you, so that when you do fall pregnant again there is already a plan of action in place. It will help your nerves tremendously to know that you've done all that was in your power, the rest is out of your hands.

After my second miscarriage I had my thyroid tested and prior to had every type of testing done possible. In my case its just nature taking its course. I think sometimes I would rather have some test show something so at least I could put a reason other than its just my body getting rid of something its finding unhealthy. Good luck

From what I know, testing is usually performed when it's 3 or more consecutive miscarriages. (I know, who'd want to go through that ordeal three times before getting some testing done. phew!)
I'd had some hormone tests and a Rubella IgG test done after the 1st m/c.
After the second, however, all the tissue obtained through D&C were sent for lab testing to know if it really was 'contents of pregnancy' or....abnormal cell development, molar pregnancy, etc.
DH & I also had a gene test done and the antiphospholopid test done. All reports were clear.
Doctor has an HSG and USG lined up for the coming cycles.

Testing depends on your medical history and will differ, person to person. Don't be afraid to try again. Wish you the very best dear.

My doctor tested my blood after two back to back mcs and found I have a low titers ANA. Basically my body attacks itself somewhere, in my case, my embryos.

And Happy Birthday!