Only 2 wet diapers.

My one month old has only had 2 wet diapers today. She’s had her normal feeding 4oz every 3-4 hours so I’m a bit concerned. She has also slept A LOT today. I woke her up from her 3 hour nap and I just finished feeding her and she has fallen back asleep as I burped her. I called the baby mother clinic in my area and they said if she doesn’t have a wet diaper after this feed this evening then I can go to the ER to have her looked over. Which I will be regardless when my SO gets home from work. Just wondering if anyone else has experienced this and if so what was the outcome.