I am a forty year old female who has not had her period for three months. I have taken two pregnancy tests, both are negative. Should I seek medical advice from a gyn.

Yes, . Yes, a gynecologist is a good place to start. She can run basic bloodwork to screen for the most common conditions that cause a woman to skip her period - perimenopause/menopause and thyroid dysfunction. There are also less common (but easy to test for) conditions such as a benign (non-cancerous) tumor in the pituitary gland that releases prolactin. A gyn doctor can also assess you for other perimenopausal symptoms, such as disrupted sleep, low libido, vaginal dryness, or hot flashes. If you are not having any of these other symptoms, you could give it one more month to see if you have a normal period before getting further evaluation.