Is Bulletproof coffee stalling weight loss?

I am doing the stop overeating program and I’m not losing after 1 week and I wonder where the issue could be: (my guess is my amount of Bulletproof coffee)

– I have 3 cups of Bulletproof coffee spaced out in the morning, with 2-3 tsps of heavy cream, and 2 tsps of grass-fed butter per cup. I do not like sweet coffee, so I never add sweetener or stevia.
– lunch and dinner which is 4 oz protein, bunch of veggies, and fat on my veg
– no flour or sugar
– no snaking, or picking, only afternoon green tea or black tea with a dash of stevia (but I don’t overdo artificial sweeteners)
– lunch is at noon, dinner at 4pm
– nothing else after that for the evening except herbal tea without sweetener, and occasionally with stevia

Thanks for the help!