Depend on where you put it before you brought it up to your face.
OP, you must not have been alive during the time of public pay phones. You would have had a stroke worrying about those handsets.
And don't even think about public water fountains, restaurant and store door knobs, handrails at amusement parks, etc. The list goes on and on and on. I think your phone is the least of your worries.
Washing your hands frequently is still the best way to prevent from spreading and catching germs! My dentist also said to check your toothbrushes, something I hadn't thought of before. Now, I run my toothbrush through the dishwasher or get a new one after I have been sick.