Fatigue, and a general lack of energy, can be one of the worst pregnancy ailments to deal with at least vomiting only lasts so long, but fatigue can go on all day. Pregnancy headaches are often related to fatigue as well. Whatever it is about pregnancy that is bugging you and making you feel like you cannot cope at work, here are some things you can try out to make you feel better if, of course, your employer is on board.
Take frequent breaks. Fresh air can do you so much good, even if it is just for half a minute. It can give you more energy, make you feel better after vomiting, and cure headaches. We've repeated this same bit of advice over and over again in various posts, but it sure deserves a mention here too staying hydrated is essential in pregnancy. Lots of the common pregnancy conditions are either made worse if you are dehydrated, or cause dehydration themselves (pregnancy nausea, diarrhea). Always have a drink of water on the go.
Make sure to wear comfortable, loose fitting clothes and comfy shoes. If you have to put your feet up at work, or bend the dress code a little, now is definitely the time. You can still look professional in maternity clothes, but your health does come first! Ask if you can do some of your work from home, if possible. At least at home, you don't have to care about the way you look or how co-workers will react to your pregnancy ailments.