Weird Bump near back legs

Hi everyone, before I start stressing myself out, I figured I’d reach out here first to see if it’s something necessary for a vet visit or if it’ll go away eventually.

I came home tonight to Trixie and felt a noticeable bump near her hind legs. It doesn’t look like it hurts her (no teeth grinding), she lets me check it and even gave me kisses while I look. I checked her skin, there’s no abrasion. It just feels like when someone bumps their head or one of those small limpoas (for all those who watch Dr. pimple popper lol). It feels like maybe a little smaller than a quarter.

She’s still eating normal and as far as I can tell, she’s still pooping. I just know that the bump was not there yesterday. Here’s a picture. It’s a little dark but where I’m pointing is where the bump is located.

How long should I leave it before it gets concerning? 1 or 2 days? Any ideas before I start freaking out? I just got her at the end of November and this is the first time this has happened.

How is the lump? Has it gone down? I bet it is a lymph node that got aggravated. The main thing I would be concerned about is why it swelled if it is a lymph node. I would take her to the vet if it doesn't get better. Maybe email the vet to see what they think?

Update:
I took Trixie to the vet the other day and I felt as though the vet was not much help (especially paying $180 just for a mere visit...yikes!). I pointed out the lump and she gave me the answer of it possibly appearing after being spayed a few months ago. She told me that now that it's been written down, and she knows the size of it, to just keep an eye out and make sure it doesn't change in size or color. That's all she could tell me.

I also gave her a fecal sample since this was a new place for us and she called the next day saying Trixie had a bit of giardia cysts in her poop. She told me that it wasn't concerning because it was non-pathogenic and as long as Trixie did not have diarrhea then we would just recheck in 6 months. I looked up the information on this giardia stuff as I've never heard of it before and most rabbits were prescribed antibiotics? This vet is supposed to be recommended by HRS and I almost feel like these matters are just brushed off. Either that or I'm being oversensitive? Not sure, but I'm already on the lookout for a different vet.

I hope she gets better! I would look for a different vet, just to be safe.

I agree! My gut instinct is telling me to get a second opinion as well. Trixie is happy and still eating/pooping normal but it's better to be safe than sorry . Thank you!