infertility specialist help! 4 miscarriages...

Topaz • Married. Dog mom. Go CAVS!
My husband and I are experiencing our 3rd "documented" but 4th miscarrage. We are both in our early 30's. We feel like our doctors aren't helping much. We were told after the 3rd "documented" miscarrage they can run more tests to find out what is happening. They are now passing us to an infertility specialist. I managed to get an appt today at 2. 
I am already high risk due to a large non operable liver tumor. I was only high risk for the second half of pregnancy when space is tight as the tumor is vascular. But effects our ability to conceive none. However after the miscarriages I will be high risk throughout a pregnany. 
Has anyone had 4 miscarrages and still had a successful pregnancy? 
And what tests should expect or request the doc to run? 
I have already had an endometrial lining test and Saline Infusion Sonohysterograph that all came back normal. 
Any inquiries are appreciated as we feel lost and desperate at this point.... Baby dust to all!