Yes, pray for yourself! No, you are not being selfish. Being pregnant and giving birth is hard work that requires a lot of strength. But we are not strong! We are weak and pregnancy and childbirth makes it so obvious how much we cannot do on our own. Motherhood makes it exponentially more obvious. We need God and His perfect strength to help us as we go.
How should we pray for ourselves?
As we prepare for birth pray for strength and health. Pray for God to show you how strong He is in your weakness.
"My grace is sufficient for you, for my power is made perfect in weakness." 2 Corinthians 12:9
Ask for God to prepare you for your birth. Hopefully you are talking to God all along about what your desires are. Continue to bring your desires to Him, but also seek His will above all else. Ask God to prepare you as much as is possible for an emergency, but also to hope for a healthy delivery. Ask Him to reveal Himself to you
This is a great post from Passionate Homemaking to help you prepare spiritually for giving birth.
Pray for becoming a mother, or adding to your children. Each time you have a child there are challenges and difficulties that come. Ask God to prepare you for that. Ask Him to help you love this baby and to sanctify you through motherhood. There are days I wonder at why God would bless us with another child and I see how much more I am becoming like Christ as our family grows. Pray for that and that you would have the ability to see it a midst the chaos and transition.
Again there are more things you can pray for, but these are at the top for me. How do you pray for yourself as you prepare for birth and motherhood?