Send Whatsapp messages from Wearable topic

Hello, I have a G Watch, and I know you can answer Whatsapp messages with it, but what about sending one when nobody actually did? i.e. begin a conversation or tell someone you're late without needing that person to tell you nothing.

I hope you can help me.

And no, not going to use SMS or other platforms. If it's not possible, please say so.