Talk to Gynecologist on Irregular Periods

My periods have become irregular. Before, I used to get my period at the beginning of every month. But for the last 3 months, I have not had a normal period.

Sometimes I only have a little bleeding or spotting, and it does not come properly. When it happens, I have very severe pain, and it is very difficult for me to tolerate.

Please help me and tell me what I should do.