My Tiger sleeps with me every night since he turned 10 weeks old. He is now almost 17 weeks.
He seemed fragile at 2 lbs but I have never had a problem with him. He is now 4 lbs. I think dogs in general are very light sleepers. He wakes me up more than I wake him. He starts out snuggling under the down and positions himself in-between my thighs. After a few hours, he will move out of that position (am guessing he's feeling hot - clash of body heat 
) and move to my side and stays there till the morning! I just love it . . . .