I am 48 years old I have been on my period for three weeks,I hadn't had one for three months.

I have been bleeding for three weeks now I am 48 years old this has never happen to me.The first 5 days were normal but now it is light but wont stop two weeks to long is this normal if I am going through the change!! and I hadn't had one for three months.for the last year it's been have one miss two have one miss one then miss two have one miss three.But when I do have one they have one normal.It's just been this one three weeks long getting very nerves can someone tell me if they have gone through this.Thank you !!!!