How can I tell when i'm ovulating?

Please don't say to buy OPK. Anyways, how do I know for sure if i'm fertile and when i'm ovulating? I always have a hard time. One day it's wet, sometimes hours laters it's creamy. Then the next day it's like lotion (creamy still kind of) then it's wet again. It always changes and I never know for sure. On Saturday, I had cramps on the right side of my abdomen. and it definitely felt like ovulation pains. But I don't remember if it was creamy, really wet.. etc that day. And I had back pain too. I don't track my temperature or buy anything to see if i'm ovulating I just try to check "down there". My periods are always irregular. Some time I get my period every 23 days or even every 19 days. Or 28. But usually shorter than 28. I never know for sure cuz what I have going on "down there" cuz it seems like it constantly changes. How can I have creamy discharge and then a few hours later today it's all wet and slippery? it wasn't egg white tho.. any help please so I can get a better understanding?! Please explain in detail. I looked online and it says creamy isn't fertile and then it says creamy is.. and some website says you get creamy discharge before ovulation others say after.. ugh so confusing and frustrating!