At work or at home, please feel free to ask for help. If you need to carry weights for more than 20 lbs, please check with your doctor for a limit and a note. If you are dealing with morning sickness try to reduce your work timings or change them to more suitable ones. Try to get your work responsibilities changed to less stressful ones if possible.
If you are not able to cook/clean, ask someone from your family to come and help. My mother in law offered to take care of me during my first trimester as my husband was in law school and I think that was the best thing that could have happened! My morning sickness was controlled in a few days after she arrived and I got delicious and healthy home made food I was craving for! Not everyone gets along with their MIL so if you don’t want to call yours that is perfectly fine.
But don’t say no to any kind of help that you can get. If your friends want to do something for you, ask them to bring you fresh food or help you with the groceries or take care of your first child for an hour or two while you catch a nap.
Our subdivision does a MealTrain (http://www.mealtrain.com/) for new moms for almost a month from due date. I think it is the best support you can get when everyone is so busy and tired after the new arrival. My point for this post is REST as much as you can because once the baby is here, you will forget what resting peacefully was!