I had my period on april 15.lasted 6 days, on may 2nd i had spotting thinking i was starting period again.but went away that same day?what can cause

Ovulation bleeding: A short bleeding/spotting episode about 2 weeks after a regular menstrual period is consistent with hormone withdrawal bleeding around the time of ovulation. Estradiol levels that have been rising during the first half of the cycle and are topping at the time of ovulation, dip a little bit before rising again, which causes the spotting.