What do implantation cramps feel like?

I’m currently 7 or 8 DPO and waiting to test. The last 2 days I have had LOTS of cramping but it feels unusual to me, which really makes me believe maybe I could be pregnant. I’ve had an on and off pressure / stretching feeling low in my uterus. Generally my pms cramps are dull throbbing pains. Have any of you experienced implantation cramping, and did it feel different or was it the same as period cramping? I’m hoping for my BFP this month but I’m also afraid that this other feeling is just something else.