Welcome Izzyd,
It is a somewhat common pattern of weight losss that the first two weeks of water weight loss is dramatic, but then week 3-4 nothing as your body adjusts. rtj is right, and here is a good explanation of why that happens. http://forum.lowcarber.org/showthread.php?t=365499

But if you are still fluxuating around 171 and you go a month without a loss of scale weight or inches, then you should possibly consider some of these tips. http://forum.lowcarber.org/showthread.php?t=460202
Dr Westman's first tip on the video is not to drink your fats...2T of heavy cream is allowed on his clinic plan for the day, no coconut oil in coffee, just enough butter on vegetables to satiety, etc. The Atkins 20 using net carbs is a good plan but if it isn’t working for you then maybe consider using 20g total carbs for a while.