Bumps on 6 month old head

Today I was massaging my baby’s head , so he can fall asleep and I felt two lumps on his head more in the base of the head.. one lump feels bigger than the other. Anyone has any idea what this can be? Bigger than a pea ( bean size )

I booked a drs appointment, but it isn’t until July 26th😫 * no fever . Just lumps 😖