What now?!

Okay. So, here is the thing. I have been eating healthy and working out for over a month now. At first I lost about two kilos and i was thrilled since it was not a crash diet or anything. But now, it's been 3 weeks since the scale last moved! Not even half a kilo for God's sake! On the conterary, I think I've gained half a kilo! What do I do? I am pretty sure I got it all right. (A healthy diet -something around 1000 calories/day, 40-60 min cardio or strength workout and I do drink a lot pf water). So, help before it drives me nuts! (Though I guess that's a tad too late, it already has).