Apple Watch Disconnecting

Hey guys,

So I woke up today, checked my Apple Watch and it had been 'disconnected' from my iPhone. I couldn't figure out a way to re-connect. I tried to reboot and hard reset both my iPhone and Watch but didn't do anything. I tried un-pairing the Watch from my iPhone but then couldn't re-pair. I also looked through the Apple Watch App on my iPhone and through settings on the Watch but couldn't find anything to re-connect them.

I ended up resetting the whole Watch, which meant I had to pair it all again and restore it from a backup. I was wondering if anyone knew how to re-connect them if they do ever disconnect again?

Thanks.