Re: Weight gain
My DS took a while to get his birth weight back up too. I think as long as you keep an eye on the diapers and the doctor is monitoring his weight, you shouldn't worry. Hopefully at the next visit, the weight will still have increased and the doctor won't have to suggest supplementing.
I did have to supplement with formula for about 2 months, and I somewhat regret that. I think if I had known more about pumping (the right way to do it and how often), I could have been using more milk and less formula. But, the most important thing is that your LO is gaining weight and growing - so that's how I make it okay in my head. :-P
Just make sure that you are BFing as much as possible. Don't try to be spacing it out and making a schedule. You can't overfeed her at your breast, so just let her nurse all day long if that's what she wants!
Good luck to you!
Mommy to Alex (born 2/27/11) and Katie (born 3/31/14)