Hi, I'm from 2ww, and saw your post in the "new" posts.
I have
Fertile-Focus, it's very good. I have it for a long time, I didn't have the patience to use it then but I have started using it again (along with OPK - POAS kind). It was great, I saw the "ferning" that it was referring to, beginning with a little "ferning" and then probably on the day I ovulated it was very strong. I did it again today and didn't see any fern at all.
It is good to use it in the morning, when you wake up. Have it by your night stand so you'll remember. Also, try to make a "chart" or log of what you see so you can see the trend.
So to answer your question, yes, you can see when you are about to O, you just have to be patient.
Hope this helps!