Toddler not sleeping

Jessi

My son is 17m. He has always been an amazing sleeper, even when we moved him to a toddler bed a month or so ago. We lay him down, kiss him, turn off the lights and close the door. He goes straight to sleep without a sound.

The last 3 days, he has refused to be put in his bed. He fights sleep so much. Nothing has changed in his routine or environment. He isnt sick. Is this a phase? How long does it last? Is there anything I can do to help him?