Differential Diagnosis for Negative Urine Pregnancy Test with Menses 11 Days Late

Single Most Likely Diagnosis

• Stress or hormonal imbalance: This is often the most common reason for delayed menses in the absence of pregnancy. Stress can disrupt the hypothalamic-pituitary-adrenal axis, leading to changes in menstrual cycle regularity. Similarly, hormonal imbalances not related to pregnancy can cause delays.

Other Likely Diagnoses

• Pregnancy too early to detect: Although the urine pregnancy test is negative, it's possible that the pregnancy is too early to be detected by the test, especially if the test is not very sensitive or if it was taken too early.
• Polycystic Ovary Syndrome (PCOS): PCOS is a common endocrine disorder that can cause irregular menstrual cycles, including delayed menses. It's often associated with hormonal imbalances and ovulation problems.
• Thyroid dysfunction: Both hyperthyroidism and hypothyroidism can affect menstrual regularity. Thyroid hormones play a role in regulating the menstrual cycle, and abnormalities can lead to delayed or absent menses.

Do Not Miss Diagnoses

• Ectopic pregnancy: Although less likely with a negative urine pregnancy test, an ectopic pregnancy can sometimes present with a false negative due to low hCG levels. This is a medical emergency that requires prompt diagnosis and treatment.
• Pituitary or adrenal gland disorders: Certain disorders affecting the pituitary or adrenal glands can disrupt hormonal balances necessary for regular menstrual cycles. These conditions can be serious and require specific treatment.
• Ovarian failure or premature menopause: This condition, also known as premature ovarian insufficiency, occurs when the ovaries stop functioning and hormone levels decrease before the age of 40, leading to irregular or absent menstrual periods.

Rare Diagnoses

• Asherman's syndrome: A rare condition characterized by the formation of adhesions or scar tissue in the uterus, which can lead to irregular or absent menstrual periods.
• Sheehan syndrome: A rare but potentially life-threatening condition that occurs when the pituitary gland is damaged, often due to severe blood loss during childbirth, leading to hormonal deficiencies and potentially affecting menstrual cycles.
• Other rare endocrine disorders: Such as congenital adrenal hyperplasia or androgen insensitivity syndrome, which can affect hormone production and lead to irregular menstrual cycles.