I'm not losing weight

Hi all,
I started my weight loss journey, again a little over a month ago. I started by just cutting my calories but wasn't losing weight. I noticed that even though my calories were where they were supposed to be, I was eating a lot of carbs. So I set a goal to keep my carbs under 100g a day. It still seems like a lot but it is under what MFP recommends I have. I have cut out most bread, all pasta, rice, pop, candy, and junk food. The first two weeks I lost 8lbs. I started increasing my exercise and water intake and am up to almost 45 mins of good exercise (30DS and Yoga Meltdown) a day but now I'm gaining weight. I know there is muscle gain involved but why is the scale going backwards? It's becoming very discouraging.