ILT - good luck today! FX that all goes well for you.
Snow - like ILT said, testing doesn't hurt. But if it's negative, remember, stress can change your body, specifically AF. And while you may not think you're stressed, you can be. After all, no matter what cycle you're on while TTC, if you're truly hoping for the BFP, it's a stressful time.
Taking my last does of Clomid tonight, I start opk Sat/Sun. Clomid cycle 1 gave me +opk on cd 14, cycle 2 gave me +opk on cd 16. Dr. said anywhere from 14-18 would be normal. FX it all goes according to plan.