Refusing food

My daughter is 2.5 yrs old. She is a great eater. She's on the small size 26 lbs but active and eats well. This morning she is refusing her food... then when offered again she gagged after the 5th bite. She is playing and acting fine.. not complaining about her tummy or anything else. But I'm a worry wart... should I be concerned? She is normally a great eater unless she is sick.

Anyone have toddlers that skip meals but are fine otherwise and eat later? Not sure if I need to take her into the doctor.

Note she ate well last night and slept well.