We seem to be having the same problems, and I started a very similar thread in "Personal experiences" today. Not knowing how I will feel from day to day is sometimes driving me nuts! PMS for a couple of days, and then nothing for a while again, and then PMS again, and so on.... I've had periods pretty close together for a while now (around 30 days have been normal for me otherwise) but this time I'm on day 31 and haven't started my period yet. Feels like I will, but have been feeling like this for at least a week now... Do you have PMS?