Naps getting really long...

Barbara

My girl usually naps twice a day, and each nap is usually like 1-1.5 hours. For the past few days her naps have lengthened to 2.5-3.5 hours.

For reference, she just turned 28 weeks today. Feeding has been completely normal and she is still bubbly as ever. Her night time sleep is also normal just as before.

Are any of your babies going through this or anything similar? Should I be worried? (FTM)