Electron Configuration and Valence Electrons. The electrons in an atom fill up its atomic orbitals according to the Aufbau Principle; Aufbau, in German, means building up..ach element has a number of valence electrons equal to its group number on the Periodic Table. This table illustrates a number of interesting, and complicating, features of electron configuration. Figure %: The periodicity of valence electrons. First, as electrons become higher in energy, a shift takes place.
I took the pregnancy test early at 2 & 3 weeks pregnant, and it came up negative twice. Yet I could feel something was different about my body, even though I had my cycle it fell short a few days, and was very light. Afterwards, I had breast tenderness, and dizziness.
The short answer is no. If the pregnancy test is negative, you are not pregnant, and therefore you cannot have an ectopic pregnancy. The long answer is somewhat more complex. There have been case reports in the medical literature of women with demonstrated ectopic pregnancy that had negative urine and even blood pregnancy tests.