Easiest I could test????

Nicole
And the wait begins. We bd the 13th, 17th 18th and 19th. I got my positive opk on the 17th. Hoping this will be our month. First time we ever did a opk test. Crossing my fingers and baby dust! Af due October 2nd. I don't know if I'll make it that long without testing. What's the earliest I could test?:)