I know exactly what you mean!!! I couldnt wait to leave work when preggas with DS....I left at 7 Months, and really enjoyed my time off!
Now that I am only working 2 nights a week, I thought i would be thinking differently this time round.... But no.....I still want to leave now LOL! I think mainly because I am just sooooo tired, and when the MS kicks in, Yuk! I think its hard to go to work when your mind is just not on the job IYKWIM....