Oo mommy, totally normal yan! A lot of us have babies na ganyan, they arch their backs after feeding or during burping, sometimes parang uncomfortable sila or naghahanap lang ng better position. One of my mum friends' baby did this too and the pedia said it's usually just them adjusting, pero kung very frequent sya or parang nagdudulot ng distress to baby, mas okay i-mention sa doctor lang para peace of mind mo. How's baby's feeding and pooping otherwise?