Stomach hurts now

I work with disabled people which requires me to push and pull them in their wheelchairs and hoyer, ezstand, and pull them up in there chairs. Of course they all weigh more then 50lbs. I just recently switched over to these kind of clients who require this kind of help. Today at work while pushing a client in the ez stand my stomach started to kill me and still hurts and I have cramps really bad. I am scared and just want to go home. I think I need to find a diff job. I looked it up and it is unsafe just to push a wheelchair while pregnant. What do you all think I should do?