Is the pump breast shield the right size? Where is the pain? Maybe try expressing at a different time of day. It's not unusual to get just small amounts with expressing.
Stools should still be loose. Preferably yellow.
If you think he needs feeding, just try him. He won't breastfeed unless he wants to. Check out the LLL website for tips on feeding cues. Best to avoid dummy if you are unsure about feeding cues or supply issues.
He shoul soon start to go longer between feeds. Tips: Feed on demand, let him feed as long as he wants, offer both breasts at each feed. Don't use dummy or supplements as they can affect your supply. Does he have episodes of going longer between feeds? How many feeds is he having in 24 hrs?
Night feeds vary greatly. But continuing to 10 months is not uncommon.but will be less frequent.