gaining weight

It could be some other things too. My fitness pal is based on averages, it isn't a guarantee of weight you will lose. If you are hypothyroid you won't be burning as many calories as average. If you move less than the average person per day (for example, you're tied to a desk job, go home and sit on the couch) you may not burn as many calories as my fitness pal calculates. Winter can be hard with longer dark days, it can make people much less active.

Also I've noted that if I eat more fiber and less fat, even though my calorie intake is about the same, then my fitness pal estimates that I will lose a lot more weight in five weeks if every day is the same as that day. If you aren't already doing so, look at the reports section to see how you are doing on things like fiber intake and fat intake. Focussing just on calories could be preventing you from dietary tweaks that would increase your weight loss.

Make certain you are counting everything, like sodas, salad dressings and other condiments, and nibbles. They can add up faster than you think.