A 29 year old lady presents with a long history of heavy periods. She says that she put up with them over the last few years as she was having her 2 children but feels her family is complete now and would like treatment. She has regular cycles every 28 days lasting 7 days. For the first 2 days she has to change her pads often and passes clots which discourages her from leaving the house. Examination and investigations including ultrasound are normal and she is up to date with her smear tests.
Which one of these is the first line management option for her?