If i'm only 5 weeks yesterday when was my ovulation? and conception? 1st day of my last cycle was feb 26

Cycle length: If you have a 28 day cycle (28 days from start of period to start of next) then about 14-15 days after the first day of your last period. So, around march 12 or 13. Cycles of different lengths might be fewer or more days after first day of menses. Just to remind you we general base your due date on LMP and not conception until we decide if the ultrasound adjusts the date.