Insanely exhausted

This is our 3rd month TTC and I'm about 6 DPO and I am insanely insanely exhausted to the point where I can't keep my head up or eyes open. I just want to lay down all day. I took a test and it's negative but it's still 10 days away from AF. Hoping this is a first early sign that I'll get a positive soon instead of it just bein pms. Anyone else felt this way early on and u wound up getting a BFP?