Hi tussya and welcome!
Don't worry, you won't have actually gained fat in such a short time and having eaten so well. Our body weights fluctuate from day to day based on all sorts of factors - water retention, exercise, food in the gut, time of day, hormones...
To gain 2lbs you would have to have overeaten by around 7000 calories, around a 3.5 day overeat. That's certainly not the case here and I think you'll find that it's just a natural fluctuation appearing on the scales.
The best way to notice the downward trend is either to weigh weekly on the same day & time or to use an app which logs your daily weight and trends the line for you. If you weigh on a daily basis you'll see the weight goes up and down like a yo-yo, but in the long term the numbers head downwards.
This is a helpful thread for your situation:
viewtopic.php?f=7&t=1006