My last three periods were irregular which they have never been before. Three months ago my cycle was 28 days, then 30, and 31. This most recent time (31) I reacted my ovulation which was late then my period arrived a couple days after I ovulated. Also have been getting this sharp pain that lasts for a couple hours or so at a time off and on the first day of my period and then it goes away. My period has only been lasting two days and the third day is spotting. The amount of blood is quite a lot and have been going through my pajamas at night.