I have looked online at ovulation calculators and my cycles but Im still having a hard time understanding. Its been 3 years since I have had a period because of an iud. However I have had the iud out since feb. My first period was in March on the 15th and it ended on the 21st which is 7 days. My second period was April 13th and ended April 17th which is 5 days and my last period was May 14th and ended April 18th so 4 days. So with knowing all of that how do I figure out how long my cycles are and the ovulation period and when I am most fertile? How do I figure out when I should be expected to start my period again?