I got my Yorkie at 6 weeks old, he is now 4 months old and has never slept anyplace else at night. He never wet in the bed either. He wakes me up and I put him on his puppy pad until he goes and then he is back in bed with us. Over the last 3 nights, we had to be out of town and could not take him with us. Both my husband and I were very lost without him at night. I kept reaching out for him and would wake up when I did not feel him.
As for bacteria and insects.......... our children had bacteria and we let them sleep with us. Personally, I think way to much is made about nothing. If a person claims that they got bacteria and insects from allowing their dog in bed with them, I think if you got the whole story, the dog was the least of the problem.