CLOMID & OPK PEAK DAYS

Sharita
Married for 8 years and TTC for the last 5 years.  Took clomid a few times about a year ago and took a break. Took 100MG of clomid CD 3-7 this cycle, the OPK has given me the peak face since CD 10. I tested this morning and still received a peak face and it's CD 21. Is the normal?