The bleeding that occurs while you take the inactive pills isn't the same as a regular period. Nor is the bleeding necessary for health. This is good news if you take birth control pills and want more control over your menstrual cycle, either for personal or medical reasons.
To prepare for the glucose tolerance diagnostic test: 1  Eat a balanced diet that contains at least 150 grams (g) of carbohydrate per day for 3 days before the test. Fruits, breads, cereals, grains, rice, crackers, and starchy vegetables such as potatoes, beans, and corn are good sources of carbohydrate.
A glucose test is a fasting test. 1  For 12 hours prior to testing, you may not eat or drink any beverage other than water. 2  Caffeine can skew the results, so you should not consume caffeine within 24 hours of the test.  Fast at night, and take the test the first thing in the morning to get accurate results.