I agree with the above posters but you can also track when you are aware with what is going on with your own body. I charted BBT for 2 years and watched CM and was right on the target when I took the OPK so once you know your "signs" purchasing OPKs becomes just a additional expense. I watch my CM ( I know it sounds horrible but really not) and am aware of breast tenderness and a bit of cramping usually from the side I'm "O"ing on.. so chart for a while and you can surley teach your self to be more aware. Hope this helps you! XOXO CiNdY
You can buy ovulation predictor kits either at the drugstore or the cheapest way is on the internet. I think they're like 50 cents each online. It detects the LH in your urine. When you have the LH surge, you will get a second line that's darker than the control line. (Then you'll know you're ovulating in the next 1-2 days.) Good luck!
by using Ovulation prediction kits (OPKs), good luck