Serious question..ladies please help!!!

Hi ladies I'm really confused. I got my last period April 20. Was due for AF again on May 20th. Till today may 24th no period and several negative pregnancy tests. I just did an opk for the past two days and got a +opk today. Does this mean I'm not getting a period for May?? What is going on here? I do have irregular period but now with tracking o's ... I have no idea what is going and how I'm ovating during the time my AF is supposed to be coming ??