AITA for telling a customer I'm not going to serve her because I'm pregnant and she's being racist towards my co-workers and accusing us of being lazy?

I work in retail and I'm 5 months pregnant. Because of this I've been moved to a cash register, which is a fixed post. This means I cannot move around. I sit on a stool while working.<br><br>There's a ropes system in place, ensuring each customer gets served in the order they arrived in. A woman came in, walked past the three people in front of her and to my register. The woman working the other register told her she needed to go back to the end of the line, and she started yelling at her, she's been in the store for 15 and not been served yet, even though she only got there 5 minutes ago, she's clearly a badseed. Anyways, she called my co-worker an idiot with no brains, because she's clearly an immigrant and therefore from a shithole country. My co-worker was understandably very upset. She started crying, and I told her to take a few if she needed to, and I would deal with the next customers.<br><br>This woman then comes to me. I looked her dead in the eye and told her "I'm not going to serve you, because you just called my co-worker an idiot. You can go to the self-scanning, or wait for the next employee to help you".<br><br>She started telling me I was lazy and I was sitting there doing nothing so I could serve her. I repeated I wasn't going to serve her, and I was going to call my manager if she didn't leave. She started yelling at me now. I asked her to leave, and security came, and along with him my manager. I told him the story and he asked her to leave the store. She didn't. So he called the police. They removed her. But not without her yelling at me and spitting in my direction.<br><br>My co-workers are on my side, but my manager said I shouldn't have been rude to a customer, and should have served her and written her up. He gave me a warning, and my co-workers are collecting money for me to pay rent, in case I get fired.<br><br>So AITA?