Yes, it can be normal Helle, but it can also be a sign of dehydration in an infant and NOT to be written off as something to ignore when they are this young. yes formula can be detrimental, but sometimes it may be needed so stop the dehydration getting worse - no one wants a dehydrated baby do they? So while it can be normal, and even common, considering that the OP also has feeding troubles, to me, that signals that the urates are not normal in this instance and when it happened to me, I did whatever I could to get fluids into my baby to get him urinating normally and if that means a little bit of formula while waiting for my milk to come in, then I'd do it. It might only be a small top up after a breastfeed and in no way does it completely ruin the BF relationship.

ETA - Jaki, we posted at the same time. I'm so happy to hear that things have improved today and that his wee is more normal.