This product worked very very well When me and my husband were trying too conceive. It was very accurate. Every time I was about too ovulate a smily face would appear. I also took my temperature the same time as using this and it was right on with accuracy. I would recommend anyone who is trying too concieve too try this out. Only problem is. If you started these tests in the middle of your cycle and the smily face appeared it wouldn't work any longer, and I would still have over 15 sticks too use. I could have used those stick for next month if I didn't get pregnant, but it wouldn't work once the smily face detected ovulation so I had too throw them away. At 35$ box its super expensive too have too throw away unused sticks I could potentially use for the next cycle. But if your trying too get pregnant and determined in the end its worth it.