Late ovulation?

Does anyone have cycles that are slightly longer than 'average' my cycles can be anywhere from 28-35 days meaning pinpointing ovulation is practically impossible without ovu tests! I am using the clear blue ones and this month I didn't ovulate until day 17/18. With my other two children I fell pregnant 1st month of trying I am now on cycle 6 and had a miscarriage last year at 10 weeks.