Totally not related to periods, sex, or pregnancy. Just my teeth.

Over the last 2 weeks, I've been clenching my teeth a lot when I'm sleeping. I've never done this before, ever. I've been waking up to big pains with my jaws and my teeth. I'm not grinding my teeth, luckily, but I'm not sure why I have been doing this. I brush my teeth twice a day and my oral hygiene is fantastic. I don't think it's related to anything in my mouth, like infections. I do give head to my husband but I've been doing that for so long but I don't think it would cause an issue now, right? I don't use my teeth for a BJ lol.

Does anyone have any guesses on what could cause this? Are there mouth guardes that I can purchase that I can wear at night to prevent any damage to my teeth?

*Please no rude comments*