Thank you for your question. Please permit me to assist you with your concerns.
I will respond to each concern that you listed. Some information may be favorable to you, some may not be, so I ask that you do not blame the messenger in those instances.
As far as your employer is concerned, legally he has a right to discipline and demand certain actions from you provided that such demands are not based on discriminatory factors. The fact that you left on your own, for example, is technically job abandonment and potentially grounds for termination
if he did not grant you leave. So while you may need additional accommodations due to pregnancy, it does not give you the right or ability to do as you see fit. Having said that, you are also entitled to be a safe working environment--there is no law that requires you to be respected, but likewise you are entitled to be treated fairly and just like any other employee.
If you do feel that he is trying to get you to quit, then arguably that may be a hostile
work environment. Provided that your boss has 15 or more employees, you can contact the EEOC
and file a grievance with them by claiming gender discrimination
stemming from pregnancy and retaliation
. That is your best bet in pursuing this if you truly feel that he is targeting you with no basis. Just make sure you also do not give him grounds to do so.