Weight changes throughout the day as I am sure you know. If you ate late the night before that might still register as extra in the morning. If you ate a lot of salty things you might be retaining water. Water levels fluctuate madly at the best of times, from hour to hour as well as from day to day.
Always weigh at the same time of day, in similar clothes. I do NOT weigh weekly because I think fortnightly or even monthly is a much better indicator, particularly for those who have a comparatively small amount of weight to lose, and it makes more allowance for water and other ups and downs that are beyond our control.
Please don't lose heart. I stalled for eight weeks but kept the faith and, the following month, lost 9lb, to my amazement. My losses are very slow now that I am in Phase 3 but still I keep the faith!
Stick with it, you will be glad you did x