7 weeks old baby eating much less all of a sudden!?

Olivia
My little girl just turned 7 weeks today. During 6 weeks she would be eating every 1 half to 3 hours and at least 20mins everytime. Sometimes she would be on and off my breast for an hour. But For the past two days she's been eating every 3-5 hours and would only eat for about 10mins. Should I be worried? Anyone else's baby doing the same?