Your loss the very first week is mostly water so don't expect to see those kind of losses long term. Your body will settle into its own rhythm, some weeks you'll lose more, some less, some STS. Try measuring your losses by the month and not the week, our bodies go through constant changes and by being slave to the scales you may get disheartened when there's no cause. Keep a close eye on your measurements too - sometimes the scales won't budge but you'll find inches gone!