Hi. We bought a lovely second hand cot and changing unit on ebay but have since found out that the mattress is a slightly non standard size. We bought one from Mothercare, squeezed it into the cot and it fit ok so we thought nothing of it. Now that LO is nearly here and we're preparing properly, we've noticed that it rucks up (because it's 4 cm too long). DH thinks it'll be fine but I wouldn't be comfy if my mattress was like that so I'm in favour of getting a different one. Any thoughts?