My Shocking Weightloss

I went to the doctor last week for my lab results/regular check up. I went on the scale and to my surprise my weight was 123, the lady who weighed me said the scale is not working so I went to weigh on another scale and my weight was 127 lbs ! I lost 11 lbs ! I was 138 lbs last year but over the past couple months my weight has drastically changed. Funny thing is I was not trying to lose weight but I have been eating less lately, I use to eat a lot but due to stress/life/etc I feel that may have caused my weight loss. I'm not happy about this weight loss at all but I will continue eating healthier. I feel my weight loss happened mostly cause I ate less junk food(fast food). I am happy however that my stomach has became flatter, my mum even said I look thin but she doesn't like it. I didn't believe until I saw my weight at the doctor.