Having Period every 3 weeks

Hi,

I am 41 years old.  My mother passed away in 1980 from ovarian cancer.  She had early menopause at 37 years old, and had her period again in her early 50's and went in for a d&c and was diagnosed with ovarian cancer.

June of 2002 I had two cone biopsy's, and from that I had my period every 28 days but were heavy periods that lasted for 7 days.  Since January 2003, I have had periods that lasted for 9 days and occur every 3 weeks, which means I feel like I'm getting my period every 2 weeks.  

Feb 17th, went to my Doctor who did bloodwork and vaginal/pelvic ultrasound.  I am waiting for results by Feb 21st.

Could this be early pre menopause? or something worse?

Help