Unusually long length of period in menopause?

My wife is 52 and has been in the menopause for at least a year now. she has had erratic periods before but the one she is having now has lasted for at least 3 weeks. she has complained of a stomach ache but insists that it is her stomach not anything else.. she is not exhibiting any other symptoms that are unusual for her recently, she does get hot flushes, sleeps poorly and is less focused and more tired. how long should i leave it (stop listening to excuses and bully her)before we go to the doctors