For working mums, do you slow down at your work, take more MCs during pregnancy?

As soon as I know that I'm pregnant and given first appt, ill inform my boss and in charge. This is to ensure they understand my situation, lessen my load. If I take MC, they would know why but as much as possible Ill find ways to reduce the fatigue and nausea so that I dont feel guilty with my colleagues that covers my spot if im not around. Though we are entitled but atleast we dont feel guilt towards others.