Thousands of congrats to you! I am just a student but when I was pregnant, my husband and I were in the middle of building the foundation of our house and the hard work is possible but the best advice I can give is to listen to your body. When we are pregnant, our bodies seem to have an amazing way of letting us know what we need when we need it! I have to admit that if it wasn't for being so active while I was pregnant, I don't think my labor would of been so easy. A few hours of contractions, then a 3 hour nap, pushed for about 20 minutes and there she was!
Now what I did is nothing compared to the work load and physical/emotional demands you will be facing. Maybe if it is going to be a bit much, they can let you work somewhere a bit slower paced? (Is there such a thing as slower paced as a nurse?)
Again, congratulations! Pregnancy is so much fun (well, more so after those first weeks of exhaustion and nausea...peppermint mints worked great for me.) Picking a name, finding out if it is a boy/girl, the nursery...and that is all before the baby! The baby is the icing on the cake!