Little bump under baby’s skin

**I WILL be having the doctor look at it but I JUST noticed it and wanted some insight before we’re able to see the doctor, so be kind please**

It’s about the size of a small bead. It’s movable and feels like it’s right under the skin. Ugh stuff like this makes me so nervous 😢 like is it nothing, is it serious? What could it be? Baby is 3 months old