I dropped my iphone5s in water and it was fine but now my homebutton won't work?

This morning i drpooed my phone in water pulled it out quickly then dried it off and it worked great then 20 minutes ago i got home and my ome button did not work so i don't now if it is water damage of if it is because i have the 5s and the home buttoons are sentisitve

Added (1). oh and i did buy inssurance

Warranty, though they may not accept it if they find water damage.