This seems to be the story with our Lincoln. I think he is a few days old in these pictures and the sleeper he is in is a newborn size. As you can see it is too short in the arms and legs and the feet are too little for Lincoln's feet to fit in. Needless to say, he did not stay in this sleeper any longer than it took to take the pictures.
Yes, our newborn son is already fitting in 3 month clothes. I have to admit, I was a little sad by this because we had bought some really cute newborn things. However, I was excited about the 3 month clothes because I found some really cute things that I wasn't sure he would be able to wear because I wasn't sure that the weather and his growth would match up.
At Lincoln's one week appointment he was 10 lbs 6 oz. I am excited to see what he will be at his one month appointment.