Lifting & Exercising while pregnant

I'm not going to my doctor until Monday, I just got my BFP Friday, and I am almost 7 weeks pregnant. I am a student, home health aide and CNA. I work in an Alzheimer's unit on Saturday's and this Saturday will be my first shift since the positive test. Is it safe to continue with the lifting and shifting of my patients that I've been doing for the past five years? Should I alert my boss and stick to light duty? I'm new at this pregnancy thing and I've read conflicting articles of what is and is not the right thing to do.