About 4 weeks ago i stopped taking the pill cerezette after being on it for 3 years, and as of yet i have had no sign of a period, but i have been getting very violent mood swings, tiredness, trouble sleeping, head aches, stomach pains and my breasts are very very sore. I have done a few pregnancy tests to which all come back negative. Is this normal and how long do i have to wait to actually see a period?