Test or not?

My 15 month old baby has a bit of a hoarse voice and a small dry cough (he coughs once/twice every few hours)

Now before anyone says anything he have been inside for the past week (symptoms have just came on the last two days) and will continue to stay in for another two weeks just incase.

Even though we will be staying inside and not been in contact with anyone etc etc is it worth getting him tested? He's fine within himself - running around playing etc. I just know the test is invasive and don't want to put him through it unless necessary