I had A LOT of days like that in the beginning. Sadly, for me, it didn't last but a few weeks...LOL I have become an expert at planning out my calories to the last .001 now! I don't give ANY up. LOL
What I did do is keep a running weekly total of any unused calories though and would sometime use them for something a little extra, like real salad dressing or a little sour cream on my baked potato. Though I then changed my plan around a little to add extra calories on weekends and by then I was "over" the honey moon stage.