Exercise can slow you up for a number of reasons. If you burn more calories more than your body needs to fuel itself, it'll feel like its starving. If that happens the COD might up your food intake to balance out your burning. If you start gaining muscle there's a period, at least that I've noticed, to get your body to "turn around" so to speak. You start gaining muscle and it looks like you're not losing anything, then all the sudden you start dropping easly again, but there might be a couple of weeks in the middle where your body is in flux. There are other things to take into account too. Drinking water and sodium in your body before you work out can help retain water longer. Every body is different though.
One thing you'll notice if you start doing yoga is this- it might not help you lose weight at all, or very little. But it's going to make your inches disappear a lot faster. You are going to elongate...your muscles will become longer and leaner and will therefore, take up less room. This is a big bonus to your clothes fitting differently and your body looking better. Yoga is awesome for this. If you want something like yoga that will also help you lose weight, try Pilates for the lengthing and weight loss effect.
By New Years: 275