I got fired from my job... for being pregnant

UPDATE: http://imgur.com/gallery/Bnxfl

So I am a server, and I've been serving at this restaurant since the end of last year. I've developed a lot of cool new friendships and have learned a lot here. This job has been the best job I've ever had because of the environment and the people. I love it.

One day we get this new manager in. We'll call him Jason. He's weird, super tall/big and socially awkward. No one likes him, but I decide to give him a chance anyway. Everyone deserves it, right? I wasn't his biggest fan but I wasn't about to let him ruin my job for me.

He got worse. The power trips, snide comments, blatant sexist remarks, it was ridiculous. We all started hating him. He treated us with great disrespect and got mad that no one liked him. Despite this, we still did our jobs effectively. He would go running to our GM (who is a wonderful manager, btw) and say how much his feelings are hurt, etc.. He always put on a show for him, so our GM didn't really believe he was all that bad.

I recently found out that I was pregnant. I'm about ten weeks along and it's not very safe for me to be doing any lifting during the first trimester, as it is risky for the fetus. I am a small person. I stopped running the heavy trays and opted for running the smaller ones instead, while also stocking anything that needs to be stocked. I'm a team player and just wanted to make sure I was making up for what I wasn't doing.

I'd been doing this since I found out and the other managers have been fine with this.

Yesterday, after the rush died down, I went to the kitchen and checked my phone. This isn't encouraged but it's not a big deal to the management as long as we do our jobs. Jason walks by and says "OP, go run food". I look at the window of food and notice that the only trays up there are too heavy, five plates of food on each tray. I respectfully tell him that I can't, they're too heavy and I'm pregnant. There were other servers standing around, so why he was singling me out, I don't know. He became livid. His face turned red and he started yelling at me. "DO YOU HAVE A DOCTORS NOTE THAT SAYS YOU CANT RUN FOOD?" No, I don't. I didn't know I needed one. I'm pregnant. He then says that I need to run food, which I'd been doing all day, just not the heavy trays. I stated this and he said that I needed a doctor's note. I got angry and yelled at him, saying that I am pregnant, I'm not endangering the life of my child for you, sorry.

He was very angry at this point. He looked like he was going to hit something and said that I was cut (which means I'm not taking anymore tables). He said he "wasn't dealing with my shit today". I'm not sure what that meant, because I'm usually pretty quiet and laid back.

Cut to checkout, when I'm giving him my money from the day, he sits down with me and says that "it's not working out." I need a doctor's note to not "do my job". I asked him, "So you're firing me because I'm pregnant?" And of course he says no. Apparently he's firing me for my "attitude." He doesn't like the disrespect and the fact that I cursed. He also said that he called our regional manager and he said it was okay ( which I find hard to believe). He told me that there's no calling my GM on Monday and getting my job back. I was furious.

So what did I do? I called my GM while he was on vacation, and I never wanted to bother him while he was there. I told him what happened, while I'm crying hysterically. He said that he will meet with me on Monday (tomorrow) when he gets back and we'll talk. I'm really nervous. I can't afford to lose my job over this. My coworkers keep telling me that everything is okay and it'll be fine, but I'm just scared. I've never been fired before. I'm a hard worker and my coworkers love me.

I feel I can work with the guy and maintain a professional relationship, but he always lets his emotions control the situation. He gets really flustered very easily and is always disappearing to call his girlfriend during rushes. Anxiety problems, maybe, but when you are manager of the front of the house we need you to be present at all times so if our guests have any troubles, it can be resolved immediately, not 20 minutes later.

I guess my pregnancy hormones are getting the best of me. I can't stop crying (I never cry haha) and I'm just emotional. To anyone who read this, thank you. I just needed to let it all out.

TLDR; Asshole of a manager fires pregnant server for protecting her unborn child.

EDIT TO ANSWER QUESTIONS AND COMMENTS:

I would like to add that another one of my coworkers was 9 months pregnant and "Jason" tried to tell her that she was lazy for not running trays. That same day, she went into labor. She did the same thing as me; didn't run the heavy trays but made up for it in other areas. It was never a problem with any of management until he came along. She also didn't have a doctor's note and was never asked for one.

I have never been written up before and I am a good employee. Top in sales and go above and beyond for the company. There are others who work here who go off on managers all the time, swearing included, but haven't been written up. They are good employees. Some should have definitely been fired because of it, but nothing was done. It happens all the time around here. I also apologized to Jason for the incident but he didn't want to hear it. I'm one of the top in sales and all around a good server.

For those saying I should run the plates of heavy trays separately, we are not allowed to do so. It causes too much confusion when someone reads the ticket on that tray when things are missing and causes missing food. I feel like people saying this have never served before... I have served at other places off and on; I know what I'm doing. Like I said before, there were plenty of other servers standing around that could have run those trays who were also on their phones. I don't know why he singled me out.