Cramping at 5dpo and 6dpo?

I had some cramping at days 5/6 or 6/7 dpo (not sure 100% what day I ovulated). It was on and off menstrual type cramping that radiated down to my hips and knees (I have sciatic pain and joint issues and this happens during my periods and while I was pregnant with my son). I'm now 7/8 dpo, no cramping but literally could not keep my eyes open so I napped while my son was napping. Has anyone had cramping and tiredness that early in pregnancy (before a positive test)?

YES I KNOW IMPLANTATION DOESNT OCCUR UNTIL 6PO-12DPO.