If you don't have to look at the keyboard then you know how to type. Don't get hung up on whether it's proper or not. When people say someone doesn't know how to type, it explicitly means they have to look at the keyboard.

however, as a programmer who does have to type a lot, using the correct fingers would help you in the long run because at some point you will have repetitive stress problems, so bit the bullet and do it. The cost is tiny and certainly nothing to fear or put off.