Recurring bootup issues on Macbook Pro

I have a 2012 Macbook Pro running OS X (10.7.5) The last two mornings it has failed to boot. I managed to boot it into recovery mode both times and run a disk repair. After that, it booted up fine, both times.

However, it concerns me that this is a recurring problem. If the disk repair had actually fixed the problem, would it have recurred?

I'm wondering what my next step is. I have a recent backup, so do I erase and restore from the backup?

Do I take my machine in to get a new drive? Do I reset the NVRAM? Do I replace the NVRAM?

Any help is greatly appreciated.