Was I wrong? Work situation

Anyways, today we had two busers on my shift. (5-8) the hostess (manager) and the other buser were in the back laughing, eating candy and telling stories about how they get drunk. Mind you we are busy and i'm doing every table by myself. I finally get a little break to take a sip of water and she says "go around and take dirty dishes off tables." Then went back to talking. I walked around, everyone was eating or still using their plates. One table had a few and I asked them if I could take them and they said they weren't sure the child was done eating. So I left. I went back behind the counter for a minute then she screams "my heada going to explode" all mad and goes back to the kitchen. (The other buser still not helping) i cleaned a table and was taking it back when i heard her and the other girls saying how i "dont do my job" i ignored it and went on cleaning. A few minutes later she clocked me out and slammed the paper down i have to sign and said "you can leave." 

Now im a quiet person, extremely shy. I have never talked to anyone there. Never. I do my job, keep my mouth shut. I am very polite so when she said that I just smiled and said "okay."

I was getting my paper to leave and she goes "when i tell you to do something, i expect you to do it." 

I told her "im sorry. I did. I walked around and the only table with dirty dishes said they werent done." 

And she then yelled at me and said "no you didnt. I seen alot if dishes you didnt even bother picking up so id he better off without you here. Just leave." 

I was supposed to get paid too and she just ignored me and left. Now im pregnant and very emotional and I left there crying because she always cuts me early and i barely get any money. 

The other workers told me that i dont do my job when im actually the only buser who does the job right. 

Was I wrong in all this? I work tomorrow and im thinking im not showing up and let them do it by themselves and quitting because i can find a job with better hours.