Hard time with maintaining

Hi I am a 21 year old female, about a year ago I lost 28 pounds. I dropped from 135 to 107 and I am 5'1. For the last 6 months I've had such an easy time with maintenance. Usually I try to eat healthy during the week and cheat on the weekends. I am somewhat active, I am a college student so I walk a lot but only go to the gym 2-3 times per week. Mfp says I should eat 1530 for maintenance and I normally eat 1300 during the week and more on the weekends. For a while this was working great, but ash of recently I've been slowly putting on 3 pounds over the last month and a half. I know 3 pounds isn't a lot but It is scaring me. I also don't want to only eat 1300 cals a day for the rest of my life,but every time I try to increase my weight shoots up even more and usually goes back down. However it has not been going back down recently.