What Causes Early Menstruation With Normal Bleeding?

Good afternoon. I am a 39 year old woman, who had her first period at 12. I am concerned because my period came a week earlier than it should have, and it was a normal period for me, lasting about 4 days with normal flow. But then I continued spotting everyday after for 3 days, and now I got what I consider to be another full on period and have had it for 3 more days. This is highly unusual for me. I wouldn t consider my menstrual cycle as regular by normal standards. However, the fact that it came a week earlier than it should have, a long with the fact it has not really gone away and I have a full flow again is worrying me. What could be causing this, and is there anything else specific I should watch for?