EBF 11.5 week old

Looking for some commiseration, a gut check, or any advice or insights! Our boy will be 12 weeks in two days. Except for some formula in the three days after he was born while still at the hospital, and a bit of pumping and bottles his first week, he has since only nursed. He was a big baby at birth and had continued to gain and grow really well.

Occasionally he would have a nursing session where he fussed a little and stopped eating sooner. However I’ve noticed in the last couple of days he’s had more nursing episodes like this. So instead of his “typical” ~18-21 min per feeding session, it’s like ~9-12 min. Has anyone else noticed a reduction in feeding time around this age (approaching 12 weeks / 3 months)?

He’s also been on probiotics for a few weeks, which has changed his poops from several daily to 1-2 max/day, sometimes skipping a day. He seems to strain more often to poop or get gas out, but when he does go it’s normal (he isn’t constipated).

Appreciate anything anyone can share — thanks in advance!!