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.
Best Answer: You can't take take a pregnancy test right after you have sex. Pregnancy tests work by detecting the amount of HCG in your urine, a hormone that is secreted during pregnancy. Right after sex, the sperm wouldn't have even reached the egg so you wouldn't even be pregnant yet.Once the egg is fertilized it still takes six days for it to travel to your uterus, and implanet itself.regnancy tests work by detecting the amount of HCG in your urine, a hormone that is secreted during pregnancy. Right after sex, the sperm wouldn't have even reached the egg so you wouldn't even be pregnant yet.