Wake issue this morning. Is this software?

I've had my phone since Thursday, and I just now experienced this.

So this morning when I woke up my phone, I pressed the sleep/wake button.

The screen turned on and then turned off. I press the sleep/wake button again and it does the same thing. I finally press it a third time and it goes to the unlock screen... WHAT?

 

This happened an hour ago, I rebooted and have been trying to replicate this. But haven't been able too... Should I worry?