Hi, breast pain
is a common problem in women, many women feel this during the second half of menstrual cycle, which may be normal. Now, coming to your problem, it seems that you experienced this for the Ist time. I don't know your age, family history of any breast problems, your breast examination findings or weather you are taking any medicines (hormones in particular) or not, so, cannot give a real reason of the pain to you. Prenatal vitamins
generally do not cause such symptoms but may lead to chest tightness
in some women in which case the prescription needs review. My advise is that; you should go to a physician get your breast examined to rule out any local pathology & switch over to some Folic acid
only preparation if you are planning a pregnancy
& eat a healthy diet. Good luck.