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.
So many TTCers have this issue. I have 2 children and used first response pregnancy test to infact tell me I was pregnant. The last test I had taken was 2 years ago. Just this month I thought I was pregnant again, so I went to the store to purchase a First Response pregnancy test. I immediately noticed the new design, wider strip and new handle.