Worried about my job and pregnancy

So I'm stressing about my job and pregnancy. 
I'm a CNA. It's a physically demanding job. I have to turn patients, pull patients up in bed, pull them out of bed, etc. 
I'm a petite girl, and pretty much all of my patients are at least 50 pounds more than I weigh. 
Has anyone in the health care field like CNA or nursing been pregnant and worried like this? 
Any experiences?