Hi there,

It's not very common to play a Dm with your pinky, and it may be uncomfortable for you to switch to/from a Dm playing it that way.

But like with most things when it comes to playing guitar, there are no hard rules for anything except the music theory behind it all. If you're able to comfortably play a Dm, switch to and from it with that type of fingering, then by all means, you're not doing anything wrong.

You have to be able to judge for yourself these types of things. I do believe it may prove to be a little more difficult for you in the long run, because of the way you have to position your pinky.

It's up to you!

Best,

Billy