8-9 dpo and exhausted!!

Ok so I’m 8-9dpo and AF due in 6 days. I’m extremely exhausted to the point where I’ve had to book the afternoon off work to go back to bed!! I had a normal amount of sleep last night (8hours) but feel like I’ve been hit by a bus. I’ve also got sore boobs and slight cramping. Has anybody had this before there bfp?