Final answer:
Chest pain is the condition that indicates a client should immediately stop taking the oral contraceptive and consult their healthcare provider, as it may signal a serious complication such as a blood clot or heart attack.
Step-by-step explanation:
The condition that indicates a client should stop taking the oral contraceptive immediately and notify the practitioner is chest pain. Chest pain can be a sign of a serious side effect such as a blood clot or heart attack, which is a potential risk when taking hormonal contraceptives like the combined oral contraceptive pill that contains both estrogen and progestin. While other listed conditions such as menorrhagia (heavy menstrual bleeding), mittelschmerz (pain associated with ovulation), and increased leukorrhea (vaginal discharge) may require medical attention, they do not typically necessitate the immediate cessation of oral contraceptive use. However, the client should be aware of other warning signs indicating serious complications from oral contraceptive use, such as unusual bleeding or discharge, lump in the breast, chronic indigestion or difficulty swallowing, obvious changes in a wart or mole, and persistent coughing or hoarseness.