First off, congrats on being so close to your goal! Awesome job!
As for your question, it's best to weigh at the same time each day, as weight fluctuates throughout the day.
I think most folks here tend to weigh in first thing in the morning, after using the bathroom but before eating anything, and feel that this gives them their truest weight. Some, though, weigh in at a group meeting like Weight Watchers, but it's still the same time and day.
There aren't any "weight police" to make sure you do it correctly, though, so whichever you choose, just make sure it's consistent. Some people weigh daily, some weekly, some monthly, even. It's up to you
. Just don't compare a pre-exercise weight to a post-exercise weight, or vice versa.