Should I contact a lawyer or not?

So I have been bullied at work for being pregnant. People out right saying I'm lazy and am using the excuse of being pregnant to not work. I work every time I'm scheduled. I'm never late and if I call out sick I always have a doctors note. Apparently enough coworkers and bosses complained that they went to HR. My supervisor told me that HR said if I didn't get a doctors note saying that couldn't lift heavy items that I had to do it and if not could be in trouble. Even though any other job they ask me to do I always do it. There are other departments at my job that don't require heavy lifting but those are considered, "promoted jobs" I told them the only reason why I didn't have a note was because on/gyn doesn't want to see me till around 8 weeks pregnant. And that I had gone to the ER  for pains and they said no heavy lifting. They gave me a work note but forgot to write the do not heavy lift. Now I'm scared that if I do t get a doctors appointment soon to get a note and I end up stressing out and hurting myself I could lose the baby. Or get fired for complaining about pain. I'm also curious if it's illegal the bullying I'm constantly getting from my coworkers about being pregnant. Help!