Getting TSH checked is good advice. Underactive thyroid can cause irregular periods. Hypothyroidism could be caused by simple iodine deficiency and not necessarily hashimoto's disorder. If the TSH test comes back normal, getting an ultrasound to check for ovarian cysts, fibroids, etc may be the next step.
Check BHCG and TSH and Prolactin emergent. Share the result, I will be here if you needed me.π
If the patient over 30 years old, we order FSH, LH and estrogen too.