Umbilical cord/stump

Miranda

So baby boy is almost three weeks old. He’s 2 weeks 4 days old. Anyways today his umbilical cord stump started to smell it’s only halfway on at this point too. And parts of it have been falling off. We have kept it dry and are doing as his pediatrician has said going around it with rubbing alcohol. But I’m terrified something is wrong. My other babies cords just fell off all at once and never smelled. My daughter’s (third baby) had to have hers treated at almost a month old to get her cord to fall off. It was on there good. They told me my son had a super thick healthy cord at birth and may take a while to come off. But the smell is what worries me. Is it a normal thing I just never experienced cause my other babies lost theirs all at once?