I've been told I have a cystic condition and its sore and swelled around menustation time, can this be cancerous? Also can fybriods become cacerous?

NO. Fibrocystic disease is very common condition affecting pre menopausal woman is a benign condition , itself is not malignant but will have slightly higher incidence . Fibroids are benign disease , rarely transform to malignant fibrosarcoma . Do not worry go for regular check ups by your doctor(s) .