Hi there, I also have weird ovulation cycles. I am not having much luck the past month with OPK kits. I'm on day 17 and still have not got the flashing smiley face or solid one on clear blue, telling me I'm ovulating. My periods are slightly irregular in that I have either 27 or 28 and occasionally 26 or 29! It makes it really hard to predict things- the ova app I have downloaded never seems to correspond with my OPK results.... argh!