Another question. Do other people have problems with a NUK pacifier?

My baby's father made a mistake to buy one pacifier that read 6 months plus, when he was 3 days old. :P. Off course he didn't take it, he was so small still. The problem is it was a Nuk and I got another Nuk for 0 months plus now that he is a week old and he tries to keep it in his mouth, but makes a face as he is having a hard time and it just falls off his mouth. Is the pacifier the problem?