Please my people help me. My cycle length keeps changing.These r the length

January to February 35 days

February to March 30 days

March to April 35days

April to May 28days

Now my problem is I had my menses on 27th April and the ovulation day I was given is 16th May. Also my next menstruation date given was 30th May . Today is 25th May n have had my menses meaning the ovulation day given to me was earlier than the 16th May meanwhile am TTC. PLEASE WHAT DO I DO1