Really terrific beta numbers!
The P4 is your progesterone level and "most" doctors like to see it above 20 or so. My doctor is never happy unless it is over 40 for some reason. But, 50 is really great.
Your E2 is your estrogen level and you are definitely on the good side there as well.
Congratulations. I hope you have a very happy and healthy eight more months. And I hope it's two boys for you.

~m