Dissapointed and learning opks

Hi guys. Im seeking encouragement and advice please. This month made it a year trying to conceive our first child. Im 23 and havent been diagnosed with pcos or endometriosis. Which is a possibility, but havent been to the doctor. I really wanted to try my best by myself, and ill seek help when i see its really needed. (most likely in the next couple of months). - Im going to start using opks after this coming up period in a couple days. All i know about opks is that the test line has to be just as dark or darker to be a positive. But my cycles have varied and are irregular from around 30 days to 39 days. So when do i begin testing? and how frequent? -Ive tried to learn about my own body and look for signs of ovulation. How ever i dont ever get any. My CM never changes. The last time i can remember my CM changing is when i was around 15 and 16. Im 23 now. It hasnt changed in years. Its always clear and thinish. Never thick, never creamy, nothing! I dont really get any cramping or anything like that. I dont notice a change in my temp. So at this point i dont even think i ovulate at all. so i plan on taking opks this month. other than that any advice also? soon?