Im working out but gaining weight?

ive been working out alot for the past few weeks and i didnt expect any drastic chnages or anything, i do seem to be loosing a bit of weight, my pants are starting to get loser and stuff, however when i step on the scale it says im gaining? i dont get it, i was 5 pounds over weight when i started but now im 1 pounds? and no its not my diet ive been eating very healthy, salads, no soda or junk foods anything. any ideas why im gaining weight?