[Thor's Pet]

When I first got Thor 1 month ago(he'll be 5 months on the 12th), his poop was normal. firm, log like, and basically normal dog poop.
A week and a half after I got him, I bought him a edible dog bone flavored like bacon....and holy wow!
The next day his poop was watery...literally looked like he was peeing when in fact he was pooing.
Everything else stayed the same tho. His energy was high as ever(if not more...lol)...his appetite was great...basically he was normal. But his poop wasn't.
So I automatically went and bought pumpkin. Cut back on treats. And just watched him. At the vets recommendation after I called him.
All the pumpkin did was make him go 8 times in that night!(all in my hallway...ugh...lol)
It "hardened" up to guey tho...but not "solid".
I kinda blew that off as his food, as I'm slowly transitioning him from Nutrience puppy food to Taste of the Wild.(and had just started to transition him at that same time)
But now, almost 2 weeks later, his stool is STILL just guey.
He is still normal in every other way tho.
He eats his half cup of food in like 5 min flat(he gets half a cup twice a day), and plays hard as ever.
I will say tho, his food transition isn't done yet....we did 3 cups old, 1 new(that lasted 4 days) then it was 2 cups old, 2 new(that lasted 4 days) then now we're on 3 new, 1 old(we're on day 3 of 4).
He's completely healthy....just his poop isn't. I've even noticed mucus in it occasionally.
He has a vet appointment next weds, to get his last puppy shots, so gonna talk to the vet again then, but is this something to be worried about?
Basically, I'll be blunt, I have the savings to pay for whatever test is NESSASARY, but would rather NOT pay for a test, if it's not, and I"m worried the vet will just want to run all types of tests, charge me an arm and a leg, only to find out it's ok, it's normal, and he'll outgrow it.
I have the savings, but I'm not rich by any means...and would rather keep the savings for emergencies the could arise, as opposed to spending it on stuff that wasn't generally nessasary.
But ya, any inputs would be GREATLY appreciated.
Thank you,
Angie