Anyone work for USPS?

Uuugh, anyone else work for the United States Postal Service? I am so sick of the favoritism in this building. Last year the manager liked me and I was able to take off as much time as I wanted during my pregnancy and afterwards. He even offered me a job on the dayshift (which is hard to get as an MHA). But another girl was fired because her first day of work was her due date and so she came to work but immediately filled out maternity leave paperwork. Now i am pregnant again and my nausea has had me at home for the last couple weeks. The old manager retired and this time I recieved a fact finder, letter of warning and now it looks like I have a certified letter waiting for me to pick up... probably termination. I mean, the union will get my job back but seriously? Do they have any real protocol for handling pregnancies? They are pretty common, right?