The procedure for medical chemical abortion is very efficient and secure. Progesterone cannot bind to its receptors on the uterus (womb) because of the abortion pill. Pregnancy growth and uterine quiescence (the absence of contractions) are maintained by progesterone. In 99% of patients who choose a medical abortion alone, the procedure is finished in 24 hours or less. https://www.womenscenter.com/m....edical_chemical_abor