Possible UTI with new kitten?

I just got my kitten Benny two days ago (Oct. 5) from the SPCA. His estimated birth date is June 6th so that puts him at 4 months old. His first day home he had no bowel movements until he jumped on the beed and peed and pooped on my comforter in the middle of the night. I immediately got up and put it in the machine washer and the next day I took him to his litter box a ton of times thinking he maybe didn't get where it was. During the day he finally peed in the litter box and I praised him and gave him lots of love and some treats. Then at night he got back on my bed and peed and then pooped in his litter box after I'd taken the comforter to clean. He's been staying only in my room which is fairly small so he should be ok with 1 litter box. He's also very confident and playful so I don't think it's a stress issue. He sometimes goes into the litter box and smells/scratches but doesn't pee/poo. I searched how often kittens should pee and it seems like it should be somewhere between 4-6 times a day and he's only peed 3 times in 2 days. Does this sound like a behavioural issue (maybe he's not too well litter trained) or could it be a UTI? Also the litter pan has a liner, maybe he's not liking that? Thanks in advance for any help and advice you can give me! 

Benny is also sterilized (the procedure was done around the 3rd of October)

It could be one of several things.

-  First off, once they have urinated outside the litter box, they are drawn right back there, unless you clean up with an enzymatic leaner.  Tossing something in the washer, or taking it to the cleaners will NOT get rid of the smell to a cat.  So...need to take care of that business

- Second, it could definitely be the litter box liner.  Some cats just don't like them, especially if they really dig, because their claws tend to get caught in them

- Third, it could be the litter you are using.  I would use UNSCENTED,

- Fourth, is the box covered or uncovered.?  Some cats don't like covered boxes

- Fifth, rule of thumb is at least TWO boxes if you have one cat.  Some cats don't want to pee and poop in the same box, and some wn't even pee twice in the same box until it's been cleaned

-Sixth, it COULD be a UTI, although unless he's also peeing somewhere other than a place where he peed that very first time, I'm thinking probably  not. 

- Seventh, my adult cats each only pee about once per day.  Can't remember about kittens, but are you feeding dry food or wet food, and is he drinking much?  I would say the amount he would urinate would mainly depend on his intake of liquids.  (OR...is he actually peeing elsewhere and you just haven't found it yet?)

Whatever you do, don't yell at him when he pees on your bed.  Do like you did and put him in the box and praise the heck out of him.  Getting upset with a kitten will just serve to confuse him.  . 

I took Benny to the vet and it wasn't a UTI just behavioural. However since I took him he has had no more accidents and is using his litter box perfectly! However I will consider your advice if he starts having any more trouble   Thank you for your answer!