I think it was Yasmine who posted on the forum and said that we should think of each pound as 2 packets of butter. Thats a great thing to do I think, helps you to visualise the weight you've lost. I'm going to go to Tesco this weekend and count out the pounds i've lost in terms of a pile of butter and then put it back !!
You'll definitely have your 4 stone next week I'd say, if you up your exersise you'll definitely do it.