you concieve half way through cycle,with this you wont get your next period.so you have a period 2 weeks later you ovulate,then another 2 weeks you get your next period,unless you concieved during ovulation,then you wont get your next period....
But how can you concieve before your last period, the fact that you has a period means that you weren't pregnant. You then ovulate approx 2 weeks after your last period.. ?
Two weeks BEFORE. The luteal phase is the phase between ovulation and your next period. That phase is usually 12-16 days long. So to figure out when you possibly ovulate based on math, then you need to subtract 14 from however long your cycles are. So if your cycle is 32 days you most likely ovulate on or about cycle day 18 (first day of your period is cycle day 1).