Wrong! Don't assume anything about what's happening with your body.

Menstrual periods commonly stop during chemotherapy or hormonal therapy. This isn't a guarantee that you are menopausal, though. Blood tests that measure estrogen levels will help determine this.

Why is it important to know for sure? Here are a few reasons:

1. If she stops menstruating, a woman may assume she need not worry about birth control. That's a dangerous assumption, especially if she's being treated for breast cancer or is on long-term hormonal therapy. During these treatments, pregnancy should be avoided, not encouraged.

2. Medications used in chemotherapy and hormonal therapy can cause congenital defects to the developing fetus. You may be thinking, "It's OK to have a baby. Bringing a new life into this world will give me happiness," but the timing of your pregnancy needs to be planned carefully. Actually, most cancer experts recommend that patients wait at least two years after finishing treatment before embarking on pregnancy. Even then, counseling is recommended before any attempts to conceive.

3. Your menopausal status will determine which hormonal therapy you choose. If you started taking tamoxifen at an age close to when you would expect to reach menopause, your doctor will likely check your blood hormone levels periodically to determine your status. Once you are truly menopausal, your doctor may switch you to an aromatase inhibitor.