Alright, so I should have already started my period on the 26 of March, which would have been 30 days after the last period (26 of February). I took a pregnancy test on the 27th and it came out negative. My cycle varies sometimes from 28-31 days. My last periods were pretty regular, 29-30 days. Now it is the 29th of March (3rd day of missed period) and I have cramps like during PMS, but my breasts are less tender than they usually would be before my period(practically almost not tender at all) and I don't seem to feel sick or anything like that in the morning. I am really gassy though and have to wee more than before. What could it be?