my fitness pal question/concern

so because i have lost a total of 15 pounds my fitness pal raised my calorie intake to 1440 instead of 1300..why is that..I'm am kind of confused on why it was raised and i did not do it.it did it once i updated my weight loss. can someone please explain to me why would your calorie intake increase instead of decrease, i know this is something i should know especially with working in the medical field but everyone keeps telling me "i don't know what to tell you, maybe its a sign to stop losing weight"..i am not listening to that answer because i am not losing weight for them i am doing it for myself and a better me in the future. since i lost these pounds my asthma doesn't bother me as much and i have been able to jog for 15 minutes without needing my inhaler.. before my weight loss i wasn't able to jog less than 5 minutes before i was puffing away. i am also losing weight because i am only 5'1" so with me being 180 at the time it was really hard to have a great self esteem..I'm 15 pounds lighter and i now feel my esteem rising and i actually can hold my head up without wondering what people are going to say about me when i leave.