I look 100mg clomid (clomiphene) & ovulated cd18 (confirmed) this month it's cd18 & still no ovulation.will i ovulate or could it work one month & not the next?

More likely ovulate: There is cycle to cycle variation as to when you may ovulate 1. If you started Clomid (clomiphene) days 2-3-4-5 and finished days 10-11-12-13, you could ovulate anywhere between 4 to 10 days after completion 2. Our practice uses ultrasounds to help confirm folllcle recruitment and timing of ovulation- as your physician if they would do that if you are unsure when you may be ovulating.