After a shakey start my 21 week old dd has slept wel, at least 6 hours straight a nighgt since 8/9 weeks. A couple of weeks ago we moved her to her cot, which meant a bit more waking but still sleeping well. However since Monday night she wont let me put her down, she'll fall asleep after a feed then however deeply asleep she appears to be she'll wake on being put down, this goes on repeatedly. She's tired and fractious, as am I. Please do you have any ideas?