Lump on Side of Stomach - Leopard Gecko

He has a small lump on one side of his stomach. I tried to get a few photos but found my camera dead, so I will later.

No possibility of being impacted; unless it was from food which it should not have been anyway.
He is eating and pooping regularly and still energetic.
His temps were a bit high today (around 99) which I didn't realize but he spent most of the day on his cool side. Neglect on my part.
He hasn't been dropped or otherwise physically injured.

I know you're likely going to say take him to a vet. I'd like to see if there's something I may have done first, though, that I can correct.

Put some photos up when you can!

Here we go. Charged the camera for like 5 minutes then snapped a few. Sorry they're not very good.

One side is entirely fine, smooth, whatever. Other side looks like this:
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SAM_2918.jpg
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Note it's a very small lump. It may have been there yesterday but the photos I have from then don't show it.

He also shed today.

I would definitely keep an eye on it and if it doesn't go away or gets bigger definitely see a vet. All I can think of impaction, hernia, rupture, or full belly.
Sorry I couldn't help

if it is not gone in say, three days, see a vet. if it is, see the vet anyways. better safe than sorry.

Would a cricket that was too large for him cause something like that? I've been wracking my brain to think if I may have done something and that's the only thing I can think of. I've been really careful to make sure the crickets I feed him are small, but I wonder if I accidentally dropped one in that was too big.

Agreed. The thing is, going to the vet is a pain in the butt and it costs money, but when it comes to the health of your animal, something you've chosen to care for, why risk it? How bad will you feel if it were to be something deadly and you didn't take it to a vet? I'm not trying to bully you, but the vet will be able to perform tests (and likely know things) that we simply cannot. Obviously no one here can make you go to the vet, but it is highly encouraged, as you already know.

If it gets any bigger, I will call the vet immediately. If it lingers for more than 2 days I will call and consult with them to see if they think I should bring him in.

He's kind of part of the family already. My fiance and I consider him to be our "child" and have since the day I brought him home. Regardless of vet bills, I want to do everything I can to make sure that he is okay. I have a pocket of money set aside specifically for a situation like this, especially since I'm not very experienced.

Been a hectic week between work, vacation planning and life.

Update: The lump went away after about a day. Called the vet and his suggestion was it could have been caused by food. If it makes another appearance, I should seek attention but not for now.

Glad to hear!