abnormal bleeding

I am 51 years old, have given birth to three children and have been told in recent years I have fibroid tumors. I still get my period. However, as of lately I have skipped a month or two. I have been experiencing bleeding in between periods and when I do get my period, it is heavier and longer than usual. They used to only last 4 days. Now I have been bleeding for 7 days. Prior to getting my period a little over a week ago, I had it just over two weeks ago. Are these symptoms of menopause or having to do with fibroid tumors. I had an ultrasound last year and the tumors were not getting bigger.