If your tsh was 0.250 with first test abdominal scan shows you have a goiter and a cyst on your thyroid but the second blood test tsh now 0.612?

Thyroid. TSH can vary slightly as in your case. On average your TSH seems pretty normal. Might want to repeat this in a few months. Mild goiter and cyst on thyroid may be related - maybe not. Depends on size and appearance. You should f/u with the doc who ordered the study.
TSH. Variation in TSH. The 0.250 seems borderline low. Did they check for thyroid antibodies ( anti-peroxidase, anti ttyroglobulin antibodies? Sometimes when there is thyroid dysfunction or Hashimotos disease ( antibodies to thyroid) initially TSH is low as the thyroid is overacitve and then rises to the point where you may need hormone replacement. Lots of women have it . Monitor and F/U w/ doc.