If you can get
trip insurance that will cover cancellation for any reason, then I would probably say go ahead and keep planning. My biggest concern is the unknown factors, like complications, pre-term birth, high need baby, etc.
My first was soooo easy! Easy pregnancy, easy birth (I didn't even know I was in labor - at my regular appointment, my midwife told me it was time to go to the hospital because I was dilated 6 cm and my water was about to break! He was born a few hours later.) He was a very easy baby. My second, I had a lot more of the typical pregnancy discomforts and was induced (although just by breaking the water - I have to admit, I lucked out on another easy delivery.) But DD screamed for the first 3 months of her life (especially in the car!) I love her more than anything, but she is anything but easy.
Germ-wise, I'd be a lot more concerned about flying than actually being in the parks. My kids seem to get sick every time we fly. It sounds like that won't be an issue for you. Still, as I mentioned before, it will be flu season, so there could be a lot of coughing and sneezing going around. Remember the severity of this past flu season? As others have mentioned, it isn't so much that a newborn is more susceptible to germs, but that it can be so much more serious if they catch something.
I guess it all comes down to your personal level of risk tolerance. I have to say that if I had an easy baby and was recovering well from delivering, and there wasn't a dangerous flu epidemic, I would probably go.
