Well, your device is water resistant (not water proof), so it depends on how big was the splash.
Crossing your fingers, if it is still working... you were lucky.
But I would suggest that you don't use it for at least 12 hours. Turn it off, fill a box with rice, bury your iP7 into the rice and close the box. Then, tomorrow morning, try to turn it on...
If you wanna feel more comfortable, have your device inspected at your nearest Apple Store or authorized service provider: Apple - Find Locations - Location Selector
Regards and best of luck