I agree with Bridgette. I would test after work. When I noticed it was getting close to positive I would test in the morning and in the evening. Good Luck!
I don't think there is anything wrong with testing later in the evening when you get home from work. I would always test between 5-6.
If you have enough tests are are afraid you might have a short surge, you can always try testing once in the morning and then again in the evening.