Baby spitting up but still hungry?

My girl is 4 weeks. I’m a FTM. I breastfeed and also pump so she’ll take a bottle once a day or every other day or so. Recently she’s been spitting up after feedings breast or bottle doesn’t matter. But then immediately starts rooting again. I’m pretty sure she’s still in a growth spurt so that’s prob part of it. But I assumed spit up meant they were full? I give her my boob anyway and she ends up still eating. She also doesn’t spit up every time but today she has a couple of times. She doesn’t seem irritated when she spits up or anything. I’m going to bring it up to her ped just don’t know if it’s normal? Anyone else’s baby spit up but still hungry after ?