House Training a Puppy?

I have a 8 week old Yorkie who stays in my room with the crate and run beside my bed. I leave his hard feed and water also in the run. He has puppy pads in here whilst potty training and during the day when he may be alone in the house for short periods of time he has a downstairs run and bed, water, etc. What if once potty trained he decides to come and do his business upstairs because he is used to this at night? Please help.

By Amelia H. from UK