He's only 9 weeks. Just an infant. He also only has a certain capacity for holding it. At this point, nothing is really taking, it's just management. You need to take him out more, too. About every 10 minutes when he is awake (they sleep a lot at this age) and immediately after eating, drinking, playing and sleeping. Take him out on a leash, and put him down in the same spot. Stand still (like a tree) and when he potties, praise him (I use "good potty!"), reward with food, play, etc. and go back inside. If the puppy doesn't potty within a few minutes, scoop him up, bring him inside, put him in a crate with something to do, and try again in 10 minutes.
Also, are you sure the puppy is just 6.9 lbs? That is quite small. I would expect his weight to be about double that at 9 weeks. Has he been to the vet?