I would mention a couple of other points as well.
The MCU you mention has an absolute maximum supply voltage of 3.6V. I would not recommend operating it normally at that voltage. 3.3V would be preferable.
The relay you mention is rated for 2A maximum. You are not giving it much margin either. It would be preferable to select one rated for at least 2x that for a little margin. A relay from this group would be more suitable.