Tom here's one that's been posted beforemtcreeklabradoodles said:
http://www.goldendoodles.com/Health/growth_chart.htm
Call the vet...and maybe like a human mom sometimes a child isn't nursing correctly, or nurses to vigorously and/or too much then they nipples can get sore, bleed etc.
Please LET me know what you're vet says.
I'll ask my breeder is she knows the growth rate in the first few weeks as I am weighing them for her now. But now they're going on 6 weeks old.