Tigz,
How weight loss manifests is non linear, you can see good losses on weeks where you did not do so well following plan. It is also possible to see gains or STS on weeks where you feel that you were fully on plan.
Draw a line in the sand and move on. Evaluate yourself over a longer period than a week. There will be many on the site who would have been very happy with an STS. Clearly it is a better result than a gain.
Regards,
Ian