Nope, Walt did not make Disney to be all about kids, actually. He made it for people of all ages, as he thought it boring and stupid to sit and watch his kids enjoy the rides at a local park. So, he created a place where people of all ages could have fun. So, WDW isn't just for kids - check out the solo/adult forum here to see what I'm talking about.
I'm not bitter, I'm not angry, just trying to give the OP some ideas about how to be able to take care of herself, and her toddler and stroller while at WDW. My life has not been sad, (well, except for the death of a dear cousin's 3 year old last year) and I am a very responsible, helpful person. I hold doors open for people, have given up my seat on a WDW bus, pick items up off the floor at stores and put them back where they belong, and have even given up two planned trips to WDW and donated the money to charities.
Oh, and by the way, it was already stated in this thread that the unborn child is well protected in the womb - so, I was comparing myself to the physical body of only the pregnant woman. Anyone standing up could get injured. I wish WDW wouldn't even allow people to stand on their buses! It's not like they are going one block and stopping, etc. They go quite fast, and some of those drivers are maniacs!
So, back to the OP's questions - if you can afford to rent a car, I'd do that. Your husband could go back to the resort on the bus, and then you could drive back to the resort in your car, not having to worry about balancing a stroller and toddler on a crowded bus.