More milk

I pump one bottle every morning for the few hours I'm away from my LO everyday. Usually, I'd pump about 2.5 to 3 ounces. The past two days, I've been getting out closer to 4 ounces. Yesterday, my 2 month old had one of those restless days and fed quite a bit. Has this happened to anyone? Is my baby going through a growth spurt again? I feel like that's a big jump in milk...