8wk old not pooping

nikilr

DS is only pooping about every 3-4 days and it is only a very small amount.  He will have small streaks in his diaper every now and then.  I'm worried that he needs to go, because he is constantly grunting and turn red.  It seems like he is trying to go but just can't.  DS has never been a good pooper, so I'm starting to worry that something may be wrong.  Does this seem normal?  I really hate how fussy he gets.  He gets very red and grunts so hard.  His 2 month check is next week and I plan on asking his pedi.