Holly,
Congratulations on your upcoming arrival! I believe that babies are a miracle, no matter when they make their appearance.
I commend you for your integrity. So few people really worry about doing the right thing by their employers, and its admirable that you are concerned. Have you considered a temp agency? I don't know what your skills are, what kind of previous experience you have, but temp agencies exist for all kinds of employees. This way, you can go to work and save up some money, without feeling like you are misleading someone.
Have you considered looking for a position with the school system? There are more than just teachers there, but cafeteria staff, hall aides, office people, all kinds of jobs in schools, and you'd be finished for the year before your baby came.
I work from home through a home party business, one afternoon a week, and make about 400-500 a month. I understand that these opportunities aren't for everyone, but if you'd like to know more about what I do, feel free to leave me a message.
Good luck and congratulations again!