All of the following stages must occur for a woman to get pregnant. however, after which stage can a woman be described as pregnant?

Pregnancy is declared from the appearance of beta HCG hormone in the woman's urine or blood. 
The hormone HCG (Gonadotropic Chorionic Hormone) is secreted by the placenta from the implantation of the embryo into the uterus. If there has been fertilization, the HCG rate exceeds 8 IU at implantation and then starts to double every other day.
So we can conclude that pregnancy is described at the stage of implantation.

An autotrophic protist - they can perform photosynthesis and mainly consist of unicellular algae. they can be divided into number of systematic group according to the shape of their cell and the type of photosynthetic pigments they use.

Um can u take a picture of the work