When does the blastocyst become an embryo?

[Antheia]

I have heard conflicting answers. One site says 4 weeks, another says 5 weeks. Which do i believe? Or is it just pretty much a guess between those weeks?

[Liz]

erm... I'm not sure! I think it's when it implants? I thought the blastocyst was just the cells dividing whilst travelling down the tubes, then it implants. Don't really know tho. That would make it more like 3 weeks tho wouldn't it.

[Alan]

Hi Tegan

Most people say 4 weeks

[Astrolady]

The blastocyst reaches the uterus at roughly the fifth day after fertilisation, and implants into the uterine wall on about day six. At this point in the mother's menstrual cycle,
the endometrium (lining of the uterus) has grown and is ready to support a
fetus. The blastocyst adheres tightly to the endometrium where it receives
nourishment via the mother's bloodstream.

During the time between implantation and the eighth week, the cells are called an embryo.

So yeah up to a week after conception going by that.

Love