Variable sleep stretches

Anyone else’s little one have a really variable first stretch of sleep at night? My LO is 10 weeks and used to consistently sleep 6 hours in his first nighttime sleep stretch and then usually another 3-ish. Now sometimes it’s 7-8 hours (yay!) but other times it’s like 4 or 5, or less. I get excited after a night when he goes like 8 hrs straight but then the next night it’s only like 4 or 5. Our days are pretty consistent so I’m hoping he’s just slowly adjusting to longer sleep and will eventually be more consistent at night? Idk. I need to stop getting my hopes up at night but it’s so hard when he does so well the night before 😫