Why aren’t perfect blastos implanting?!!! BFNs...

<a href="https://glowing.com/glow-fertility-program">IVF</a> doc said my last 2 5-day blasts were “perfect,” stim response perfect, uterine lining and hormone/thyroid blood tests perfect... husband has no issues. BFN!!! Why aren’t they implanting in this perfect scenario?

Im 42 and in great health. Fit, healthy, exercise regularly. No stress. Pre-genetic testing is too $$$ for us, BUT is it simply my age or possible DNA/chromosome issue the ONLY reason that my embyros aren’t implanting?

Ive been pregnant before twice (both MC 8 weeks) and have no physical/uterine/tube issues.