I am going to privately test AMH, day 2-5 bloods and DHEA when my cycles return. I can do that with finger prick tests from Medichecks and I can work out what the results imply. I am 44 though so that's more to check ovarian reserve and my age-related fertility.
Other tests for recurrent miscarriage include Antiphospholipid syndrome tests, thrombophilia profile (full blood count,
coagulation, anti-thrombin 3, factor V Leiden, Factor II prothrombin
gene, MTHFR gene, lupus anticoagulant, protein C, free protein S,
anticardiolipin abs) and karyotyping.
I will wait for these until we have been to the recurrent miscarriage clinic though they usually only investigate after 3 or more losses. The possible causes I want to rule out are low progesterone, auto-immune or that one of us has balanced translocation (this could have implications for our daughters). It may just be a chromosome abnormality due to our ages though.
The thing is, I am not sure that these tests help particularly as with DD2 (when I was 32) I had to go through 3 losses to conceive her as a viable pregnancy. For me, it is more a matter of getting a better idea of my risk factors and whether I do want to continue ttc at my age, if I am likely to suffer more losses as I am quite undecided.
There is a big difference between trying that in your 30s for a second child and sibling, to my age and with DD2 we just got on with it. The main benefit of earlier losses (5-6 weeks) has been that my body would reset fairly quickly and I could move on to the next cycle, which really helped. The losses are really important as they got me where I wanted in the end and I had to go through them to get DD2. Even this recent one has been informative.
If you are spotting early and therefore have a threatened miscarriage you should be able to get progesterone if you have had 2-3 previous losses. My progesterone levels were on the low (riskier) side, but I never had any spotting. The other thing my EPAU said was to refer straight to them for any subsequent pregnancies.