Thank you for your prompt reply. A major concern I have is that this employer may refuse to provide me with a letter of reference, or be a good reference for me, if I proceed with legal action. I work in a small town and he knows almost everyone in my industry. He has indicated that he will provide a letter of reference but emailed "it's best to wait until my maternity leave is over" but that I can list his phone number for now. This kind of makes me feel that if I pursue with legal action I may not have a good reference for my last 3 years of work.... If I do proceed with legal action is there a way to ensure he does not tell any future employers of a lawsuit or a way to get him to still be a reference for me?
I also have a Maternity leave of absence form stating my actual days away from work, actual return to work date, and comments that I would be returning to work under the same title and pay in my existing employment agreement. This was signed by myself and my employer on August 2, 2012. Does this help your argument that something's not right about this as I have this signed form from him?
Is this a Human Rights argument as well? Could he be discriminating as I'm woman? What specific type of lawyer should I use?