HELP/ADVICE!!! Is my boy losing too much weight??

My newborn (born 10/15/19) arrived at 7 lbs 10 oz. It was an emergency csection, but otherwise everything went fine and he was perfectly healthy.

By the time we left the hospital, he weighed 7 lbs 1 oz (came to find out he was just not latching correctly and wasn’t getting enough milk). I have been feeding him breastmilk exclusively, switching between the bottle and breast. With the bottle, he’s eating 50 ml per meal (every 2-3 hours).

We just got back from he pediatrician this afternoon and he weighs 6 lbs 14 oz! The pediatrician didn’t seem concerned at all, but I can’t find anywhere online that newborns will lose additional weight after they leave the hospital.

He’s 2 weeks today and I’m incredibly concerned, but again, the pediatrician didn’t seem worried and said that as long as he’s eating well and urinating often (right now he’s going about 8 times a day), that we shouldn’t worry.

I know newborns that are fed milk tend to gain their weight slowly compared to formula fed babies, but it’s the additional weight loss that I’m SUPER concerned about.

I need to know, have any of you experienced this?

Should I seek a second opinion?

Am I doing something wrong?