L.R.
If the smell is this strong, I would call the pediatrician's office and ask to have him checked out. Urine smells can be signs of many different things, some totally not a problem (change in diet, not likely for your baby), and others that are serious (type 1 diabetes, though that usually creates a sweet smell). Better to check than to wait and find out something was going on that could have been taken care of earlier if you'd gone to the doctor.
Please....don't fall prey to what happens on Mamapedia all the time-- mamas who post that they "don't want to bother the doctor for nothing" or "don't want to seem like a panicked new mom" etc. This is why the doctor's there and this what insurance is for! We can't diagnose your baby here. It could be something or could be nothing -- and if it is nothing, give thanks. (If it's nothing and your doctor makes you feel bad about coming in to check it out -- find a new doctor!!)