What Could Cause Irregular Periods, Missed Cycles, And Nipple Pain While Using Protection?

Hi doctor, I have a problem.. I am 35yrs old woman and some times I will stay 2 months without seeing my periods, sometimes it comes 2 times in a month, right I experiencing painful nipples and my partner and I use protection, last month they come 2 times and this month it was only a blooting for one night.. What would be the problem?