Bump in ear

[Snicks and Buns]

Hello! I have a 6-month old bun, was just spayed about 2 weeks ago. I’ve since noticed that she’s been keeping one ear down, not all the time, but fairly often. This evening I was giving her pets and I felt her ear had a bump inside. Not deep inside, about halfway up the ear near the edge. It’s about pea sized, maybe a bit more flat. It’s not super red, but it is warm to the touch, and it is firm, not squishy or moveable. She didn’t seem to want me to touch it but it could’ve just been because she didn’t want me holding her. There’s no skin issues around it, as far as I can tell, nor do I see any bugs near. She doesn’t seem to favor the ear much more than laying her ear down flat while the other stands up straight, nor does she tilt her head or shake it.

She is otherwise in very good health. She runs and plays and chews on damn near everything she sees (including me). And she has no problems eating whatsoever. I’ve attached two pictures, one with my finger right beside the bump. The darkest red spot on the vein would be about where the bump plateaus. The other just shows the width of the bump. Otherwise there isn’t much to see.

Wanted some advice before I make a pricy trip to the vet. Is this something I should keep an eye on until it gets worse or take the vet to examine now?