Sonogram showed 1.1 cm nodule on my thyroid , blood work is fine.. should i be worried ? what are the possibilities of it being malignant ?

Evaluation : Of solitary thyroid nodule includes ultrasound and scan. If it is solid and "cold" (on scan), there is a finite possibility that it could be cancer. At your age, most likely form of thyroid cancer is papillary type, which is usually cured by surgery alone. Ask your doctor about specific details for workup and treatment.

Common problem: Small nodules of the thyroid are very common in women in your age group. Most of these nodules are benign. There are other characteristics that can be seen on thyroid ultrasound that would make one more or less suspicious. We will typically biopsy nodules larger than 1.5 cm, and observe nodules under 1 cm. Your nodule is borderline for biopsy. A thyroid scan is usually of no assistance.