HELP!! :( Unexplained weight loss :(

Brynn
So this past week has been very strange for me. About 2 weeks ago I weighed myself and I weighed about 156. Now today when I weighed myself I weighed 143. I haven't been intentionally trying to lose weight and I have been eating normally. Does anyone know what this could be due to? :( trying to save a trip to the doctors office :/