What is this? Driving me mad!

Emma • Hi im Emma, im 29 years old! I have 2 children one 6 one 4 and trying for a much wanted 3rd baby to complete the gang!
So im ttc number 3! 
Im roughly 5 days past ovulation & i have had a weird feeling not quite in my tummy but lower down since yesterday & it hasnt eased off. Its hard to explain like a bloated crampy dull ache kind of feeling. AF isnt due till a week on saturday either so it definetly isnt that plus i dont get these symptoms before AF. Any thoughts girls??