Lifting for work.

I'm 4 weeks and 4 days pregnant. I already have a lot of back pain because of my job. I am a CNA and constantly have to transfer residents from yhe bed to wheelchair and what not. Some people say lifting doesn't matter until the 2nd trimester. What would you guys do whould you stop lifting. I dont want to have a miscarriage. I read somewhere that if you life in the first 12 weeks you are more likely. I would ask my doctor, but im getting my insursnce together and can't go yet.