Firstly, while all 3 of mine smiled around one month, I am pretty sure that your baby is totally normal. I think I read a thread on here a while back where most people said not to be worried until at least 3 months old.
Secondly, you said he doesn't make eye contact much, and looks past you. It sounds to me like his eyes are still developing. (Also normal.) Do you live in a darker house? How much exposure does he get to the contrast of light and dark? He is probably looking past you because he is noticing your darker outline compared to the wall, or something similiar in the distance. Also, in the beginning, babies see better from the sides of their eyes (the peripheral). It is not unusual for them to turn their heads away and look at you from the corner of their eyes. Anyway, I would purposefully sit near a window, or otherwise up his opportunities to compare and contrast the shadows and the light. Their brains have to do that before they are ready to comprehend the more detailed images of faces. Don't read that he has an eye problem. It isn't that. It's a normal adjustment of the brain processing the visual input.
But...I'm sure he's fine. 7 weeks is still pretty young.