Re: period pain
There are a number of side effects associated with the use of birth control. Menstrual pains and cramps are usually only a common side effect for progestin only contraceptives.
Another cause for menstrual pains are prostaglandins (big word, I know). Prostaglandins are chemicals produced by a woman's body that cause many of the symptoms associated with menstrual discomfort.
You see, the tissue that forms the lining of the uterus is actually what makes these chemicals. The uterine muscles are stimulated by prostaglandins and contract. Women who have high levels of prostaglandin experience more intense contractions of their uterus thus... more pain.
Because you are over the age of 25 and because the pain is suddenly worse or different from what you may have experienced before, I recommend you go see your obstetrician.