normally i get my cramps up to 24 hours before the bleeding starts and i am also quite irregular. I also found on clomid that i had some very light cramps after ovulation and up until my period on and off... You can get cramps a few days before, and perhaps during it. It is normally before you take you periods this happens and it is very common. Irregular periods could be caused by stress and worrying. I always get cramps 2 or 3 days before my period. You'd probably be safe to test now. I don't get cramps until the second day of my period, but my oldest daughter gets them a week before. get a bit achey 3 days before, then on the day it can be quite bad.