Issues at work

Recently my manager at McDonald's has been treating me differently. It started when I told her I was pregnant. I don't think it's jealousy, I'm quite positive she doesn't want kids, she admitted she couldn't even handle taking care of a dog for a week.

But she's been denying me breaks, forcing me to carry heavy stuff, and today she even told me I wasn't allowed to go to the bathroom! After I told her we needed something (which happened to be extremely heavy) from the back, she snapped at me to handle it myself. So I did, and she sent me home for doing so! Does this qualify as discrimination? Is there anything I can do??