Constant pressure? Opinions??

So for the last 3 days I've had this really weird cramp/constant pressure feeling to my baby-making parts. I'm really irregular and can only guess really that I O'd about 5-7 days ago (doing opk but didn't catch a blazing positive this cycle). No spotting or anything, besides being an emotional disaster today (seriously, a soap commercial just made me cry). AF never makes this feeling unless she is full swing and she hasn't made an appearance yet. Any ideas ladies?! (Or gents?). Comments really really appreciated!