Cat not using Litter Box

I need some help my cat is about 6 mths old, he has been having "frequent" accidents and not using his litter box. Twice now it has been on the bed blankets within 3 weeks.
I don't know why he is doing this. He has a small litter box, could that be why? His litter is the same, the box is fairly clean... I can't think of why he is doing this. All I know if he keeps it up my husband will make me get rid of the cat.
I haven't gotten him neutered yet, do you think that might help at all?
He's an indoor cat... and doesn't roam the streets at all.
HELP before I have to get rid of him.

Before you think of "getting rid" of him, you must take him to the vet for a checkup. Urinary tract problems - like crystals or UTIs - in neutered males will cause avoidance of the litterbox.

YEs, his intact status could be contributing to the problem as he is just coming into sexual maturity.

He has a small litter box, could that be why? His litter is the same, the box is fairly clean..

A small litterbox that is not clean could also cause problems, since there are cats who refuse to use a dirty box.

If he checks out okay at the vet, get him a big litterbox and scoop it more often.

When cats stop using the litterbox, the vet is always the first place to start.

I made an appointment with the vet for tomorrow night. They told me he needed to be up to date on his vaccines 2 weeks prior to neutering.
The Receptionist said that there could be two reasons why he isn't using his litter box... (Just to let you know, I cleaned out the litter when I got home last night, and in the middle of the night he pee'd on my husband's work pants). either he has a medical problem or he is marking his territory.
There was no reason for him not to use his litter box last night because it was cleaned out. He's an overall good cat, he doesn't scratch or anything, he's loveable, cuddley and has a wonderful temperment with my 1 1/2 yr old. But him not using the litter box is an issue mainly with my husband. I don't want to "get rid" of the cat, and i don't want to lock him up when we aren't home. He is barely left alone, during the days my sister-in-law is home and in the evenings we are all at home.

I"m glad you're taking him to the vet and he will be neutered.:)

Please let us know what the vet says!

One of my guys was doing the exact ame thing your cat is (he peed on the bed, on any coat left on the floor, on shopping bags left on the floor) he was 9 months old at the time. As soon as I had him nuetered it stopped completely!! He has only ever gone in his litter box since (and is now 12 years old) :)

I believe having him nuetered ASAP will stop this behaviour.

Here is the Update on Oreo!
I took him to the vet last night and he has a clean bill of health.
The vet suggested a bigger litter box and make it as inviting as i can. I have booked him to be neutered next week and the vet said 98% of the time that fixes the problem. He also mentioned that the cat can be stressed, how I don't know, but if worse comes to worse and he continues we can put him on drugs to reduce his kitty stress. Go figure. The cat is a good tempered cat, never hisses, scratches anything... just in the past couple of days he was being naughty. He knows he's done wrong, because now he can't go into any rooms, bathrooms or the basement he can't sleep with us and he knows it.. Last night was the first night since this all happened that he went to my husband he's been avoiding him since he pee'd on his work pants...