hi im new to this site and im hoping for some advice. well my last period was on the 2nd of december and i have been getting pains all around my stomach and sometimes stabbing pains.i have also been having heartburn and indigestion for the last week. i noticed 3days ago the skin around my nipples have gone darker and the glands seem to be more noticeable and look slightly bigger and different to what they was.i have done a home pregnancy test which was negative,how come i am getting symptoms but a negative result