You cant. The monotior costs $175-$200 new and it reads the sticks. You can buy it used, but it stores your test results and uses averages if you miss a day, thats why I bought new. It's not like the cheap throw away readers that come with the tests. You keep this reader and buy the sticks. The $20 ovulation readers didn't work for me, so I bought the clearblue easy fertility monitor and strips to try. I found out that I ovulated on appx. my 18 AND 19th day. I got pregnant in 5 cycles with it. I looked at the sticks results and couldn't tell the results from looking at them. The test also shows when you are about to ovulate.