Need help with my alapaha blue blood bulldog puppy and her aggression during playtime?

My puppy is 13 weeks old and she is normally the sweetest puppy in the world, but sometime during playtime she gets a little aggressive. The big problem is her biting, we will be playing with a toy or something and out of no where she will start to ignore the toy and go for my hands my feet or anything she can reach to bite. when I yelp ouch she just gets stand offish with me and will bark a few times, I have tried the yelp, doesn't work. giving her a toy to bite instead of me, doesn't work. Ignoring her, doesn't work. finally I have resorted to crating her, something that have never wanted to do but it seems to be more effective. She also gets very dominant with other puppies like by pinning them past the point of play where the other puppy is yelping. I have never hit her once, until i started crating her for biting i only used positive teaching methods, she loves meeting new people. I know she is in the teething stage but this seems like something other than teething. has anyone else had experience like this? is this just a phase? i just want to nip any aggression in the bud because she is so sweet i don't want her to hurt somebody accidentally. any help will be greatly appreciatedThanks!-Ryan

Its the "all positive" sht Ryan, you act like prey by screaming and reacting to the bite, the dog treats you like the prey you are. Want it to stop treating you this way? Next time it tries it, pick it up by the scruff, all 4 feet off the ground, hold it at eye level and tell it to knock the sht off in a low voice devoid of emotion. If you do it right, meaning you dont punk out, it will probably crap itself and that will be the end.

Take your hand and hold it over its mouth,lay it on it back, and firmly say "No". Hold this until your dog is calm. Trust me. Read about it if your unsure but it works. Your dog can continue to become more aggressive into adult if not taken care. The method I've given you comes from a study of how dogs behave in the wild and the mother does a similar routine on her puppy to show it let it know its being too rough.