First of all ur cycles seem to be infrequent and irregular I would suggest you to meet us at clinic or online consultation through paid portal Usually u hv to count backwards from the date u expect to have menses 14 days the date that comes add and substract 2 days to give u a five days window which is favourable dates to keep contact for conception There are kits available for detecting ovulation but understanding those through this portal would b difficult Please meet personally for further evaluation and discussion