Advice please!

Allie • Ttc #2
Today I am 6dpo , I know too soon to tell anything. But since day of ovulation, I've had this fullness feeling to my uterus and been very very crampy. Sometimes quick sharp pains but cramping non stop. I never had any signs of implantation when I got pregnant with my daughter. 7days til AF. Anyone have anything similar happen this early on? Or can give me a opinion?