LATE PERIOD AND CRAMPS.

Hey ladies, I just wanted to know your opinion on something. I'm in my 20's and I suffer from polycystic ovaries. My periods were never regular but for the past 4/5 months they seem to have some what regulated themselves. My period was "due" on the 26 of last month, it's now the 13 of June and still nothing. I've had cramps for the past 2 and a half weeks which I thought was my period coming. A few days ago, I had a few light drops of blood which I thought was my period about to start, but when I woke up the next morning, there was nothing. A few days have passed now and there's still nothing. I'm still having cramps. What do you think it could be? I've been in a relationship for 4 1/2 years and I've never been pregnant. Thanks x