How soon should I tell my job


My job was eliminated due to Covid until schools open up. I was able to get a job as an overnight stocker at a grocery story. There are times that I am expected to lift heavy things or pull heavy things. I am about 4 weeks along. I am the only female on my crew except for my supervisor. I am only planning on staying there 2 more months but it may be longer if schools don't open up as expected. This is my first pregnancy so I'm not sure if I am worrying too much. Thanks