1 The heart's internal pacemaker regulates and times the beating of the heart via electrical signals.  Electrical signals start at the SA node, causing atria contraction, and then move on to AV node, delaying electrical impulses to allow blood from the atrium to fill the ventricles.
With the First Response new Early Response Twist Pregnancy Test, you can test as early as 6 days before your missed menstrual period. This is the only test that allows you to find out this early, as it is sensitive enough to capture the very scant amounts of the pregnancy hormone.
There are two types of pregnancy tests that will determine whether you should start preparing for a new member of the family or not. There are two types of blood tests. Quantitative HCG and Qualitative HCG. The good thing about a blood test is that you can take the test within 7 to 12 days of having unprotected sex. This means it is more effective than the urine test. However, the results take longer. This is because your doctor will have to take your blood sample to the laboratory for testing.