Hi. Wow, 7 weeks is a little young to be dependable about anything except kisses and chewing. My doods always went out just before bed, about 10:30pm. Until they were about 10 or 11 weeks they sometimes peed in their crate. I hate to confess this, but I didn't get up with them in the night at all, after the first week - mostly because it didn't seem to make a difference in whether they had an accident or not and they didn't wake me up. However, I was fastidious about cleaning up with enzymes, and to be honest, I did a lot of cleaning up that first two or three weeks.
Eventually they had dry nights and by about 13 weeks they were only rarely having accidents. A lot of it is just being patient until they grow up a little...they really do figure it out...some dogs earlier than others.