what time to test with opk?

please help me out i want to start testing not sure when to do so?
we are startingt to TTC#2
AF started jan 4th (just ended) i think my fertile days are 12th-17th/18th im thinking i might O on the 15th.
so my question is when is the best time to pee on the opk strips??

thank you mamas

I would personally start at least 3 days before you expect your first fertile day. I've read before to start testing around CD 10. The first month I started using OPK's I started around day 6 I think, because I didn't even know when I ovulate or even IF I ovulate due to PCOS. I used Internet cheapies so I had a bunch of tests. Anyways, that month I O'd on CD 9. The next month on CD 8 and again between CD 15 & 16, which is what I got pregnant from (the second time I ovulated that month).

Quoting ✰ Mrs. B ✰:" I would personally start at least 3 days before you expect your first fertile day. I've read before to ... [snip!] ... The next month on CD 8 and again between CD 15 & 16, which is what I got pregnant from (the second time I ovulated that month)."

thats neat! thank you!