Can anyone help me

My cycle length usually average 28 29 or 30 days... my last cycle lent was 29 days. My period came on fed.24 2015 than March 26 than April 23 and on May 22 my period supposed to been due June 20th of this month but I started having cramps ect June 15th June 16th I started spotting only noticeable when I wipe June 17th I also spotted off and on today June 18th it's kinda of a flow very light at first but now as gotten darker light a period