I've Had 4 Sonograms Done Over The Last 6 Years

I've had 4 sonograms done over the last 6 years looking at my ovaries in 2010, 2011, 2014, and 2016. The sonograms discovered cysts in both left and right ovaries. The right cyst was characterized as simple then complex and has shrinked from 1.6cm to 1.1cm since 2010. But the left cyst went from simple (2010 &2011 2.8cm to 2.0cm) to complex (2014, 1.5cm) to "hypoechoic mass" (2016, 2.4cm). Is it likely that the mass is malignant? What are the best and worst case scenarios? I'm going for a follow up sonogram in 6-8 weeks.