Hi roxy, first of all, let me reassure you that by what you are experiencing, it seems highly unlikely that you are pregnant. in case you are a lady in your 20s or 30s, irregular periods, increased appetite and body soreness point to a likelihood of Polycystic Ovarian Syndrome. but additionally, apart from all these, u must also be experiencing weight gain, fatigue and malaise, hair on your face (particularly chin) and severe pain/cramps during menses. i am sorry but I didnt really get what u meant by bipolar. if u suffer from bipolar disorder, then the medications prescribed like valproate or carbamazepine or lithium or antipsychotics, will all predispose you to the above said syndrome. in case you meant mood swings, you again increase my diagnostic pointer of PCOS. anyhow, you need not worry. PCOS is not as grave. simple treatments like weight loss, birth control pills, metformin and exercise can setright your system. but before that, we shall need to run a battery of blood tests and ultrasound of the pelvis. pls get back with your reports, if any done till now, or meet a gynaecologist soon. get well soon!