Baby spitting up after each feeding?

For the past few days, my 4 week old has been spitting up after each and every single feeding. Sometimes it seems like she has spit up the entire feeding. She’s formula fed and sometimes breastfed. This just started happening over the weekend (maybe Friday). She doesn’t seem like she’s having an issue gaining weight, but the constant spit ups (sometimes it’s a little bit, sometimes it’s a lot) is starting to get concerning. My first never really did this, so I’m at a loss. I know some spit up is normal, but I’m assuming not after each feeding. I burp her after every ounce, so I know that’s not the issue. She has a check up on Friday, but I’m wondering if anyone has dealt with this before?