So sick of walmart!!

I have worked for walmart for 8 months now. I loved my bosses and got along great with most people before i got noticeably pregnant. I'm 23 weeks now and everyone is all about the baby. I love that! But yesterday at work, my boss asked me to build a feature, not a big deal. Except i was going to have to move 18, 32lb bags of dog food first. My doctor told me nothing over 20 lbs. My boss knows this. I reminded him, and he responds with" you're not THAT pregnant"! I was furious! I was the only person on the floor and couldn't find anyone to help, i finally went up to customer service and asked a guy friend up there to move them for me. My boss actually got angry that i didn't move them! Wth!! It's not like i don't do everything that I'm asked to do, I'm just not going to disobey direct orders from a doctor!! When i go to work tomorrow, I'll be carrying another doctor's note directly to that man!