My Tiny Baby Girl by Cali

I have debated a few weeks now just how I was going to address this. It's a touchy subject, and I still feel guilt in someways, and I can identify why part of the time.
All of it started on Oct. 25th. My oldest had a pretty nasty cold, and his school insisted we go to the dr. for a note. So to the office we went. As the dr. wrapped up his appointment (which was, "it's just a virus, probably a cold"), I told him I was worried about the baby, that she had felt lighter. He said what I had been hoping, that I am probably getting used to her weight. He sent a nurse in and we had her weighed, she was 12lbs 14oz. I felt my stomach crawl into my throat. The nurse reset the scale and began telling me it was a good weight, she stopped when she saw the look of panic on my face. I told her that 2 months prior on Sept. 9th she weighed in at 15lbs. The dr. came in to talk to us briefly, he didn't push us to use formula, but told me we would stay vigilant for the time being, and we would weigh her at her six month appointment on Nov 5th. After a SNAFU at the dr. office when we were six minutes late, I took her to the Lactation Consultant that runs the group I had attended in the past. She weighed in at 12lbs 10oz. It was a long long weekend as I waited to see her dr. at our rescheduled appointment on Monday. I spent much of the weekend on google looking desperately for parents in the same boat as me, I came up empty handed.
Last week she saw her regular ped. and a ped specializing in breastfeeding. My mind has been put at east a bit. On Monday her regular ped (who also happens to specialize in Failure to Thrive cases) recommended that we add formula to her intake. What does that mean? I pump between feedings and at night, when she gets that pumped milk, formula is mixed into it as if it was water, it increases the calories. I was reluctant and very surprised when the Breastfeeding dr. agreed on Wed. I had to get over my mental formula block. I had to really get it through my own head that formula is NOT evil, and that I am not in anyway failing my baby, but I would be failing her if I didn't do everything I could to change what was going on.
It's been difficult, I can't lie. I spend a good part of my day nursing or pumping. But I am doing my best, and that is why I am okay with it. Right now I am looking to buy or rent a scale to measure her intake, and make sure she is gaining. I will keep posting, because I am sure that there are other parents out there that are going through this, or have been through this.