Thank you I also took another one today and it is still positive. I have read that you can test after the first one until you get a negative one and when you have a negative one then you have all ready ovulated.
SnowPrincess is right. A positive OPK does no mean you're ovulating yet...it means you're just about to, and that you're entering your most fertile period. Basically, your body creates an LH surge to trigger ovulation, and this is what OPKs pick up on. Once you've detected the surge (positive OPK), you should ovulate within 48 hours or so. Oh, and no need to take another test. It's the first positive test that counts. Best of luck!