Thanks for the query.
Some amount of fluctuation in the menstrual flow and menstrual symptoms is common.
Many factors can affect the hormonal
levels leading to this.
If the pain is severe, once consult gynecologist and get examined.
Then with her advice go for ultrasound
By this workup the possible cause for your problem can be identified and treated.
If you have any pelvic infection
, you may need one course of antibiotics.
If hormonal imbalance is found, you may need hormonal pills to regularize the menstrual flow.
If doctor recommends go for thyroid