Heavy periods that stop suddenly

Patient: My 17 year old daughter started her periods at age 13 and they’ve always been irregular. They are now a bit regular but very heavy. She says that the flow is heavy and then just stops – that there isn’t a gradual decrease in flow. Is this normal?(I’ve been to the dr with her but the medic just wants to put her on tranexamic acid, without checking if my daughter has eg, fibroids. She’s not sexually active) .It’s the heavy flow that stops abruptly, that doesn’t make sense to me. Is there anything sinister going on ?

Symptoms: heavy periods