Hi, I am a 22 year old female who has been having regular sex for the past few months. About two weeks ago I started noticing loads of pimples on my face and chest, tender breasts, mood swings and a really obvious dark ring around my nipples which are also sensitive. My period was due a week ago, I had some spotting a few days early and a few days after it was due but no real period. Have done home pregnancy tests which were negative, except for one which was a very faint positive and a blood test was negative. If I am not pregnant, what else could be causing these symptoms?