Yes, you are correct, it very much IS discrimination. The only thing is, I really want to work at this hospital in the future and I can see where some employers would look down on it a bit. So, that's kind of a catch 22.
I know that there are no guarantees, but I really have every intention of taking a very minimal maternity leave (4-6 wks) and working right up until the baby is born. As I said before, this isn't my first pregnancy, so I kind of know what to expect, and I feel like I will be able to juggle it.
Anyhow, I got the job offer! (and while we did not discuss the pregnancy in the interview, I was visibly,as in 6 months, pregnant at the time!) I have requested a meeting with the manager and I will get his feel on it. Obviously, he isn't going to take the offer back. But, if he seems to think that it is not going to be a good fit for the unit, I will decline the offer and wait until after the birth.
Thanks to everyone for their opinions and insight.