my biggest fear if this fet fails!

I had my second fet done Monday October 3rd, I'm not very excited about it since my first one failed. I have no symptoms at all, I'm taking my prenatals abs progesterone injections everyday, I feel like I'm doing everything right, just like last time, but I'm scared I'll get the same results! My biggest fear is that something's wrong with my embryos, we have 4 left and I'm worried they're no good.. anyone have success with a second fet with no symptoms at all!?