Implantation or early period?

So I am 10dpo according to my ovulation charting this month. I’ve had a little bit of cramps the past few days. I had this “spotting” yesterday morning but it went away. Today I got it again. I did test this morning but it was negative. My period is supposed to be due next week. Also, my back hurts so bad today. What do you all think? Implantation or period?