Blastocyst The developing hollow ball of cells that grows from a fertilized egg, before it implants in the uterus. Related Articles: Yes, You Can Take Plan B All of the Time and Be FINE!Contrary to a commonly misguided belief, the morning after pill isn't "the abortion pill." Really, it's no different than your traditional birth control pill. Sasha Co- Founder of Psych n Sex, previous writer and campus educator for the Kinsey Institute & published psychology researcher. Manhattan girl obsessed with post ww2 abstract expressionism, beet juice, vintage clothing & Scandinavia.