You are over reacting OP. no one is saying that they would deny you work just for the sake of it because you are pregnant FFS 
I was saying that I would want the information that you have that will affect my child in order to make a descison about whether we want to use your services.
And now you are calling people selfish because they want all the facts available before their child settles with you. I think it's you that is being spectacularly selfish. You have seen from this thread that some people will feel that they wouldn't want their child to start with you in these circumstances, yet you are saying that your right to work is more important that a parents right to have all facts available to them when deciding on who to leave their child with. That seems pretty selfish to me. You have your own interests at heart, not those of the family you work for or the child you care for.
For all you know, this family will be absolutely fine with your pregnancy. But they might not be and that is their descison to make because their child has not started with you yet.
Can't you see the difference in the situation you are in, where a child isn't yet with you, and a situation where you became pregnant after a child had settled with you?
FWIW, I wouldn't not be at all stroppy in a situation where you broke your leg or became ill, because that is something you wouldn't have foreseen. You wouldn't have had the option of telling me about that in advance like you do with your pregnancy, so I wouldn't be left feeling that you had been dishonest and withheld information. It's completely different. I also wouldn't have a problem with you attending routine dentist or drs appointments if you handled those things well. They can be a brilliant learning opportunity for children, and if you made the most of that I'd be more than happy for you to get on with it.
Two weeks worth of maternity leave is unusual for a reason. That's reason being that a mother needs time to bond with her new baby. And no, I don't believe the quality of care you can provide for another child when you have a newborn is the same as when you don't. There is a big difference between looking after your own baby and toddler and your own baby and someone else's toddler. I can't believe you refuse to see that. When I first had my 2nd baby, the best quality time I had with my older ds was when their Dad came home and I could give him a proper amount of attention. I could look after them perfectly well together and keep them safe, but I couldn't play as much as I could while I was still pregnant, simply because newborns need a lot of attention.