First morning urine smells

When changing my baby diaper I noticed over the last few days that her first morning pee stinks. As the day passes my baby urine smell return to normal. Is this normal for babies first morning pee to smell? ( I took my daughter to her pediatrician they collected a urine sample and found no sugar or blood and now they are sending my baby urine our for a culture and will not

get the results until Monday. I though it was dehydration at first but I’m constantly making sure my baby drinks plenty of fluids because it is extremely hot where I live.