Those are normal nap times you're getting out of your baby. My eldest daughter would take cat naps during the day and sleep like a rock at night as a newborn until she started walking, which was when she decided NO MOAR NAPS EVVARRRRRR! HA HA HA HA! It's just how she was. Since I got to sleep at night and she got most of her calories during the day with only one night feeding, I didn't complain. Turns out she's ADHD.
With my other two babies, they napped well and slept well at night. We were blessed.
My brother's baby girl has always napped horribly for him. She's predictable, but naps 15 minutes here and there and sometimes for half an hour. When she stays the weekend with me she sleeps for 2 1/2 hours. There must be something in the bed feathers here. :-)