Cramping 4 DPO?

Sammie

I had period like cramps this morning for just a couple of minutes, what can this be from?

I posted my cycle chart below because I'm not sure if I'm technically 4 or 5 days DPO, or if that even changes anything.

Quick Edit: I do track ovulation with OPKs and temp :) I am very regular and ovulate the same day every month.