Why doesnt my kitten suddenly like the litter tray?0?

i have had my ragdoll kitten for about a week, and as soon as we got him showed him the litter tray and he took to it straight away, i have another itten aswell and at times they would sit in it together more than happy. the past 2 days however he sat on the rug in the room ( its a shag rug, so quite deep) and done a wee, he also found a tissue box and went for a wee, the room isnt mive so its not like the litter tray is far away. he hasnt done a poo anywere other than the tray. should i take the rug out the room?