@bigsecksa - There's a full baby after 6 seconds, Einstein

Yes, there is a full baby at 6 weeks. The "clump of cells" may not look like a person to you, but try to keep up with the science.

This is no longer the dark ages or even for that matter the Enlightenment, where physical size is some sort of metric which we use to determine what species an animal is part of. Though let's be fair, a newborn deer mouse is less than half an inch long which puts him about the same size as your 6 week old baby. 

Indeed we know that what makes a life form a specific species isn't their size or what they look like (or, obviously, whether or not they are literally dependent on a landlord) is genetics. The crazy thing about genetics, you see, is that we can identify which species a cell is from even when it's detached entirely from the rest of its body. We can take a cell from your (physically) adult body, take a cell from a 6 week old fetus' body (well as a practical matter we don't yet have the technology, though there are techniques to obtain it around 12-16 weeks from other sources), send them both to a genetics lab and the researchers can tell us all sorts of things about the two human DNA packages they received. They can tell that one of the cells is from a fetus, true, but that would be the same if we sent them packages from an adult and fetal horse as well. At no point are they going to look at the fetal cell and think its from anything other than a human.

So now that we've established that the cells are human cells, what else are you looking for? You've already admitted that they are a "clump" of cells, thinking it was some sort of snark. But so what? You're also a clump of cells, just a bigger one. Remember we came in here pointing out that "bigger creature cannot be the same creature" is a long-discredited piece of biological fact. Now it's true that if we, say, cut off an abortion-defender's arm it wouldn't be a separate human being, it would be a detached human arm. Clearly there are clumps of cells which we would call a person and another clump of cells we would call just a part of the person, right?

The difference ends up being what is referred to as an organism:
An organism refers to a living thing that has an organized structure, can react to stimuli, reproduce, grow, adapt, and maintain homeostasis. 
Your detached arm isn't a living thing that can grow and reproduce. Is it even a living thing?
A living thing pertains to any organism or a life form that possesses or shows the characteristics of life or being alive. The fundamental characteristics are as follows: having an organized structure, requiring energy, responding to stimuli and adapting to environmental changes, and being capable of reproduction, growth, movement, metabolism, and death.
Admittedly this starts getting circular fast: an organism is a living thing which ____, and a living thing is an organism which ____.

So is the fetus an organism, yes or no? Notice that "being dependent on a landlord" doesn't factor into this at all. In fact, a living thing "requires energy" which makes a fetus no less of a lifeform for needing nourishment from his/her mother than an adult is less of a lifeform for needing nourishment from DoorDash. Does a fetus have an organized structure? Yep, Arya already admitted it. Requires energy was implicitly included in his tweet, the fetus does respond to stimuli and adapts to environmental stages and in fact does this even before implantation occurs, and obviously it's capable of reproduction as it is in fact reproducing as it grows. It's not capable of having sex and producing another offspring, but neither is a 7 year old boy and nobody is claiming children aren't alive until they hit puberty. That the fetus is capable of death is of course the whole issue with abortion!

By any biological definition that wasn't written on papyrus, the fetus is a living organism. As I am sure I've written before yet cannot find any posts on the topic (because Google is now horrible at the thing they were founded to do), we can pinpoint the exact moment when a fetus becomes its own living organism:
A membrane surrounding the egg, called the zona pellucida, has two major functions in fertilization. First, the zona pellucida contains sperm receptors that are specific for human sperm. Second, once penetrated by the sperm, the membrane becomes impermeable to penetration by other sperm.
This is now what's called a single-cell embryo which begins mitosis. In other words, once the first sperm penetrates the egg this lifeform begins to exhibit everything required to be life: the egg itself is no longer part of the mother in the same way an abortion-proponent's arm is part of the abortion-proponent (before we take a hacksaw to it). Every cell in that arm has the same DNA as the cells in the other arm, or the legs, or the kidneys, or the colon, or the nipple (barring cancer or some other exotic thing which doesn't disprove anything). The egg cell had the same DNA (but the wrong number of chromosomes) as the cells in the mother's arm or kidney as well. Until Burt Raccoon the sperm shows up. The fertilized egg now combines the genetic material from both progenitors (to borrow the insane Spanish terminology) into a unique new organism. It's what we refer to as a miracle, both in the religious sense but also believe it or not in the scientific sense. It happens, but its also kind of astounding.

It's the creation of a new life. It's science, some of that new stuff they've been working on the past couple hundred years. Arya needs to try and keep up.