Judging by another post your LO will be two weeks on Tuesday? They allow them two weeks to regain any birthweight lost and really they should only be weighing on day 5 (although in your case there were reasons to weigh on day 3), day 10 to make sure things are going in the right direction, and day 14 or 15 to make sure birthweight has been regained. Any extra weigh ins than this can be misleading. If you have the right amount of wet and pooey nappies I wouldn't worry too much. My youngest was weighed on day 5 and had only lost 5% of his weight, however he then gained not a bit between day 5 and 10 and may have even lost a bit more as my home baby scale can be up to 2oz more than the scale at the local clinic. However he had plenty of wet and dirty nappies and he was born with quite severe water retention, they aren't sure why which may have artificially inflated his birthweight and the weight on day 5. Due to a colossal mix up he wasn't officially weighed again until he was a month old but my home baby scale showed he started gaining again on day 11 and by day 15-16 he had regained the 7oz he had lost. He then gained bang on 7oz a week from then on until he got poorly at about 4.5 months, lost 4oz and gained a bit more slowly for a few weeks, then started gaining 5-9oz a week, the past two months he gained 1-2lb a month when the average for his age, 7.5 months is half to one pound a month. If weight gain hasn't improved on Wednesday I would look into the possibility of a tongue tie or other problem with milk transfer. Good luck!