Pregnancy & working full time in care

When you are pregnant and work full time in care are there any policy's that can protect you? My job requires me to do shifts where I'm out the house from 8am one morning til 8am the next morning. I do a 15 hour shift which is 8am til 11pm then sleep 11pm til 7am then work 7am til 8am and finish at 8am. They are really hard and stressful shifts and just wondering if there is anything that is in place so I don't have to do these shifts? My partner doesn't want me to work away that much and we are also under staffed at the moment which means I am doing at least 3 of these a week. Iv heard horror story's of people having miscarriages ect when being on these shifts & they are by them selves so no help or anything.