Dogs have the tendancy to go potty where ever they did previously , thats what we call teritory marking , now since the nose of your puppy is not at its full potential it fails to find the previous spot, since the bladder is very small the puppy cant hold it for a long time thats why u are having problem in your house,,, usually puppy like to go on the carpets.beds or any soft surface,, all i can suggest is you can keep record of the potty time (usually after the wake from sleep or after they eat) and as soon as you know its time for him to potty u have to pick him up and take him to the place where you want him to go , keep repeating this till your puppy is capaable enough to smell his scent long distace ,, usually it might take 4 weeks but the main task is BEING CONSISTENT.