I love that you're being so proactive about this! I bf both my children exclusively to six months and then in addition to food until 14-15 months.
First of all, it is NORMAL for babies to lose 10% of their body weight the day or so after birth, not counting IV fluids as PP have mentioned. And if the cord is clamped immediately, that might even be a little higher.
My DD was called "failure to thrive" at six weeks. Well, first of all, we'd been waiting for 2 hours at the doctors office before they weighed her and she'd had two bowel movements and been too distracted to nurse. So my first point is that ONE low weight does not make failure of anything or require supplements.
Second of all, doctors seven years ago--and most doctors now--did not have the World Healthy Organizations revised growth charts for BREASTFED babies. If you compare a bf baby to a chart for formula-fed babies, it doesn't work.
And, third, babies have different metabolisms/builds. My daughter is now, at seven, tall and lean and still about 90% height and 50% weight. She eats like a bird, but it works for her. My new pediatrician (yes, I left the one with the 2-hour wait and the "failure to thrive" diagnosis :-) compares her to her own previous measurements/growth---not to kids with heavier builds.
All that's kind of off-topic, except to say that nothing can replace your own instinct and research. You don't HAVE to supplement for jaundice!!!
On topic--I was engorged with my first and never with my second. My first had a hard time latching, I had sore nipples; my second was a breeze. I know other people who've had easy first and bumpy second babies--it all depends! My first was a snacker--less than ten minutes a side VERY often, my second was a marathoner--20 minutes a side (yes, 40 total) but not as often. And, btw, I didn't have much luck pumping--I only used a hand pump--so I could never "measure" what they ate. I just went by the number of wet diapers and whether they seemed content after each meal.
You've gotten some great advice. I also recommend breastfeeding on demand--that's pretty much constantly the first couple of weeks and then during the growth spurts, but settles into a schedule otherwise. But it will be your schedule and your baby's, not anything that anyone else dictates. And they do get super efficient after a while--you'll wonder if they got anything and they're just doing a great job getting it out!
Get support now! If you don't have access to a lactation consultant (and a lot of midwives and doulas are also LCs), then start going to La Leche League meetings now. They love having expectant moms, and it's fun because a lot of moms nurse their kids right there in the meeting and you can see what normal is at all different ages. Plus, they know all the books and articles that I've read but can't remember right now!
HTH, and happy baby!