Keep it up! These little losses all add up. If you lost 2lb every week, that still makes 8-10 lbs off every month! It all adds up! I remember when I did WW earlier last year, I felt the same as you and got a little disheartened that I wasn't losing weight faster. I then promptly put my WW stuff in the cupboard and forgot all about it. If I'd carried on, I'd have been a lot closer to my goal than I am now!
Stick with it, because how would you feel in a couple of months time if you quit now? You'd probably be thinking to yourself, "I could have lost over a stone by now." I know that's how I tend to think when I don't stick to diets. Think how proud of ourselves we can all be when summer comes along and we've all kept it up and are looking gorgeous!