When to test?!

Kristin • Married 2014👰🏼 miscarriage October 2014🌈baby boy December 2015💙 baby girl due July 2020💕
Im trying to figure out when to take prego test. I got a positive opk oct 5-6 af due thurs 10/16 so I'm about 7-8 dpo.
​I have been cramping and back pains. I want to test but is it too soon? Don't want to also test too soon
​Any advice? Please please