Working evening or night shift during pregnancy

Hi mummies, I am now 10weeks+ pregnant and working as a dialysis nurse in private company..Used to work any shifts before i got pregnant but now i find that working evening feel much tiring..my nausea and vomiting also started to get worsening lately at night time..sometimes i feel stressed and struggling to accommodate my work schedule and assignments..most colleagues know that i am pregnant but i don’t understand why sometimes my manager still putting me in evening shift with mostly we are working only 2 staff with full numbers of 7-9 patients..i just don’t want to risk myself if something happens especially if I suddenly unwell or any of my patients require emergency attention. Any opinion about this?#advicepls