Oo, normal lang yan, mama! Ang breast milk talaga may slight sweet taste pero after a day or two sa fridge, may mapapaos or slight sour-ish aftertaste dahil sa lipase enzyme, hindi siya spoiled, yan lang talaga ang chemistry ng milk mo, and some babies don't mind it at all. A few of us moms actually noticed the same thing at first kaya we were worried din, but the pedia assured us it's totally fine as long as your storage is correct (which sounds like yours is). If the smell turns really off or it looks curdled, that's when you toss it, pero based sa description mo, sounds like your milk is doing exactly what it should! Get-back-to-work feels are real, mama, you've got this.