Prenatal yoga DVD opinions?

I'm looking on Amazon to purchase a yoga DVD. I want one that will stretch me and make me stronger and ready to go the distance through pregnancy (staying fit and flexible) and obviously (hopefully) help me prepare for delivery. Any suggestions/links would be helpful. Or even if it isn't yoga, I'd love a good prenatal workout. I have done Beach Body's T25 and loved it. I really enjoyed the circuit style. I'd prefer them not to be too long. Maybe each workout being half hour or so? I'm open to anything, especially if you can tell me about it if you've done it.