Customize "Do Not Disturb" Function

Is it possible to customize the "do not disturb" function on the Apple Watch?

After buying the Apple Watch, I always leave my iPhone on "do not disturb", so as not to receive the same notification twice. My intention is: the watch vibrates and, only if the notification interests me at that moment, I check my phone.

And it's been working fine for whatsapp notifications, instagram and many other apps. Whenever I receive text messages, my watch vibrates and I check my phone if necessary. However, it hasn't been working for calls function. I mean, having my iPhone on "do not disturb", whenever somebody calls me, I don't receive the call on the Apple Watch screen to decide if I answer, or not, on the phone. Does any one know how to fix this? Or any solution to "dribble" this problem? Thanks a lot