Hi Angela
Yes, it will. If you know that you O already you could wait until after O and start the cream for 14 days. If you're trying to shorten your cycles pick a day that you will start the cream regardless of O. Using the cream before O can suppress O but I don't necessarily agree with this. I think it just depends person to person. For instance, if you look at my chart I started NPC 8 days before my O day - then I stopped the cream cause I wasn't sure if the temp increase was from the cream or O. I am now 5 days off the cream and my temps are still going higher. So, I now believe that I had a true O afterall. Hope this helps!
Crystal
PS
Its real important to chart temps - if you aren't charting are you just guessing on the O date? Charting can really help any questions about what is going on with your body.