I'm worried about my 6 1/2 month old son. Specifically, I'm worried that he shows signs of autism.?

He smiles, sometimes laughs, and makes eye contact, but has a hard time holding the eye contact. Curiously, he makes the best eye contact from a bit of a distance -- he normally avoids eye contact up close or when being held. He generally does not like being cuddled -- it agitates him -- but he loves nursing and being held in order to see things better (i.e., he prefers facing out). He coos but does not babble. He also does not imitate us and often does not look toward voices -- we have to work to get his attention. He is pretty social, though -- he loves meeting new people and watching people, including children and other babies. I know it is too early for a diagnosis, but am worried he is showing some early warning signs for autism. His doctor says he is too young to tell....