Yes it's normal, my DS put on roughly between 10 - 16 oz a week for the first 4 or 5 months. He was a very hungry ebf baby! My HVs were happy that he was feeding so well and thriving. It does slow down eventually but he has stayed hovering around the 91st centile ever since. Congratulations, you will soon have biceps of steel!
You should be very pleased at such positive signs that your LO is thriving on your milk.
My DS (now 2yo) put on similar weight in the first few months of his life. He was 7lb 8oz at birth. He'd doubled his birth weight by 8 weeks and by 7 months had nearly quadrupled it, weighing 12.6kg, which is about 1.5kg above the 99.6th centile line on the chart. Did nothing for my back. My parents were insistent I should cut back his milk (despite being EBF) to prevent obesity, but the HVs all said you can't overfeed a BF baby.
Fast forward a bit - he obviously just really tanked up during the first few months of his life as his weight remained the same after that for over a year, and now at 2yo he's only 14.5kg.
You'll find people later saying that big babies need more than just milk, but I never had any problems in that respect. Mine was EBF till 7 months (as he had various colds at 6mo which delayed weaning) The only issue for me was that it made weaning to solids very difficult as he just wasn't hungry in the second half of his first year and only wanted milk. He was still 95% reliant on breastmilk at 1yo but started to eat more solids once he started walking.
HV is coming on tues, I've had him weighed at the baby clinic each week, he's following the top line perfectly on his red book. He was a big boy at birth (9lb 7oz) and has just kept going!!! He's got to sliw down soon, my poor back can't take much more! Lol!
My two both shot up through the centiles, putting on more than three lbs a month for about six months (DS split his skin at 5 days old - literally it just peeled off him all over like a snake shedding). I'm sure your DS is fine!
I think if he is EBF that may just be the size he is. Newborns (and he still counts as one) take as much milk as they need to keep them going and no more ime. If he seems happy in himself and has wet and dirty nappies, then just be proud of yourselves. You are obviously giving him some pretty good stuff. I'm sure tiktok will be along in a bit and can give you more reassurance.
My son is 6 weeks old and for the last 4 weeks he has gained a massive 12 or 13oz every week! He is exclusively breastfed, never formula, he feeds for 15-20 mins at a time, feeds every 3-4 hours and sleeps for England!! Should I be worried about this rapid weight gain? - he's literally growing before our eyes x