Two miscarriages at 42 years old

I have a 20 month old son. My husband and I are trying for baby #2. We had two back to back miscarriages. Currently undergoing fertility testing. So far everything looks good after my first ultrasound and blood test. I have my Day 3 ultrasound next week. Has anyone gone through something similar? Just wondering if we should ttc or hold off until we complete all fertility testing? This process is so confusing!