2 IVFs with PGD and neither worked. Why?!?

I don't understand why this happening to me. I'm so depressed. I stupidly thought if we did IVF with PGD and only put chromosomally normal embryos in, it would work. But it didn't. Twice. Why not? Lining was good, hormone levels good, everything seemed perfect. Can't believe $30,000 just poof disappears and nothing to show for it except weight gain from all the hormones. It's not fair!!!