Though people sometimes treat pregnancy as if it were an illness, pregnancy is normal, and therefore almost anything you choose to do while you're pregnant won't hurt you. There are exceptions, of course. Using drugs, tobacco, or alcohol is dangerous in pregnancy, and certain high-risk activities that could result in your falling aren't a good idea. But in general women can do all their normal activities while pregnant. Since you are a custodial worker, I'd advise you to be careful about inhaling any high-powered cleaning solvents (use a face mask and gloves if there are fumes), and I'd suggest that you be good to yourself and not try to pick up or carry very heavy objects during this last stage of pregnancy. Most of all, follow the clues your body is giving you. If you feel fine at work, then all is well. If you have troublesome symptoms such as cramps or headaches, then talk to your health care provider.