Im trying to get pregnant for 3months now, my period ended on 12th july but started bleeding again on 20th july when i was suppose to be ovulating so ?

Regular cycles?: A woman with very regular periods can estimate her ovulation day this way: mark on a calendar when her next period will begin (that means mark the first day of her next period), and just look back 2 weeks to see her estimated day of ovulation. So, if her next period will start Monday Oct. 28, then Monday Oct. 14 is her estimated ovulation day. The estimate is +/- 2 days (life is not exact).