Hello, Irregular periods is caused by hormonal imbalance (like prolactin, oestrogen, progesterone,) hypothyroidism, reproductive tract infections, PCOS, anemia,fibroids, stress etc, you need to be examined first to find the cause, don't worry all can be managed with medicines please consult a gynecologist. Stress, anemia, hypothyroidism, infections All these can cause body ache, low calcium levels could cause weakness and joint pains, please consult a gynecologist first, full body check up on useless without having a provisional diagnosis at mind.