Everyone's weight loss journey is different. It is not a simple as A to B, its a long and winding road with many obstacles along the way. As long as you get to your destination it doesn't matter the route you take.
If you have chosen to have a cheat day once a month then have it - guilt free. Don't count or criticise.
Enjoy it and then back on track till your next one. If that is how you cope then there is nothing wrong with that. It takes a lot of will power to be able to do that and get straight back on the next day.....I know I couldn't do that.