 Your fecal cells are producing estrogen. Now I want to show you what is going to happen with estrogen over the course of time. Remember, we start out with our fecal cells being practically non-existent, but follicle-stimulating hormone and luteinizing hormone are encouraging these guys to start growing. So as they get bigger, we start it out with estrogen kind of whatever, as they get bigger, bigger, bigger, bigger. More and more cells are producing more and more estrogen, and we actually hit a peak of estrogen right in the middle of your cycle. Do you think this might have anything to do with ovulation? Because what was our whole point? I mean, we're talking about all this because your body, ladies, every single month, what? It prepares you, prepares your uterus to be a baby apartment for nine months. And every single month, you're prepping for this. So the whole goal, like we're setting everything up so that we can keep a baby in there for nine months and make more of ourselves. So this was estrogen. It's increasing. Now before I tell you what estrogen does, I think it would be remiss of me to not, like, give you a little heads up about progesterone because progesterone is around. There's a small amount of progesterone in the body at this time. In fact, I want to make that lower, so make it a little bit lower on your drawing. Progesterone is kind of doing its thing, but toward the end of, toward the end of this time that we're talking about before ovulation, progesterone is going to increase slightly. And it increases slightly because my granulosa cells are going to produce progesterone. Now I'm stopping this right here because those granulosa cells which are starting to produce progesterone, we're going to have somebody else take over the job of progesterone after ovulation. Progesterone doesn't play a role in the actual ovulation itself. Okay, so let's talk about what estrogen does do. And don't forget the fact that our granulosa cells are still producing mad amounts of fluid here that are doing their fluidity thing. Okay, so look at this. This is crazy talk. First of all, estrogen. When estrogen first starts to be made, it has a negative feedback on follicle-stimulating hormone and luteinizing hormone. Estrogen feeds back. In fact, I'm just going to make a little note right here. Estrogen feeds back and says, uh-uh, uh-uh. I got the follicle going. The follicle is getting big. And we don't want any more follicles. Estrogen is kind of like, I got this. Let me do the job. This continues until, well, I'm not going to tell you when it continues until, but we'll just say that it is preventing other follicles from doing their thing. Estrogen, what is it doing besides telling everybody not to make more follicles? Because look at that. Holy cow, we're getting a lot of estrogen in there. Well, estrogen is basically preparing you. It's the ultimate preparation for being fertile. If you think of fertility, think estrogen. Estrogen changes your cervical mucus. Okay, so anatomy. We have a vagina. The vagina is just a tube. It's like a muscular tube that a penis goes in. The penis goes in to deliver the sperm, okay? So this muscular tube is connected to, there's my tube, and it's connected to the uterus. The uterus is the baby apartment, where the little fetus is going to embed and like eat the wall of it and all that good stuff. At the base of the uterus, I mean, the fetus is in there, and after nine months, it needs to get out. So there's actually a hole, and sperm. Sperm need to get in. So there's a hole in the base of the uterus, and that's the cervix. The cervix sits down inside your vagina. The vagina just, this bugs me, so I have to say it now. You can't see a vagina. Like usually we're like, oh, ladies have vaginas and men have penises, but you can't see a vagina unless you go into pap smear view. Then you can see the vagina, because it's just a tube. It's a muscular tube. What you actually see, the external genitalia on a female human, it's called the vulva, and it's made up of labia majora and it's got other structures, but the vulva is what you actually see. The vagina, no, you can't see it. But anyway, my cervical mucus gets like all fired up because of estrogen. All fired up, what does that mean? It gets super slippery. Now, I'm not joking. Cervical mucus, like not under the influence of estrogen, cervical mucus is like a briar patch of walls and fortresses and like dead ends and trick passages for sperm. So if sperm go in without the influence of estrogen on your cervical mucus, they're like not going anywhere. They probably aren't even going to get into the uterus because number one, estrogen kind of opens up the cervix, makes it a little softer, makes the whole little bit softer and nicer so that the sperm can actually swim through there. Estrogen makes the mucus nicer to swim through. There are actual little tracks that the sperm can get on and like zoom in through the cervical mucus. The cervical mucus under the influence of estrogen's rule becomes sugary, full of sugar for the sperm, sac lunch and a slippery slip slip and slide and water park going all the way up like holy cow that cervical mucus is like, come on in fellas, let's do this thing and make a baby. Thank you, estrogen. Estrogen does some other things, but of course, estrogen is not only preparing you to make it so that your system is fertile. Estrogen even changes your pH. Your pH of your cervical mucus changes to become less acidic, which is friendlier to your friendly little sperm-y friends who are coming to hopefully, well they hope, they're going to find the jackpot of the egg that doesn't live for very long. Okay, so what was I telling you? Oh, we have to get the apartment ready. Like the apartment is all empty because dude, you just had your period right here. It was the first day of your period, which means that's actually your period blood is lining of the uterus that falls out. And so now there's no lining of your uterus anymore. Well, estrogen's like, I got this. I'm also an interior decorator. I can go in and make it all puffy and fluffy and nice and we'll add some pretty little like crazy molecules of proteins and fats so that just in case fertilization takes place, the little embryo can actually eat the walls of the apartment. That's a true story, a little disturbing. So basically, estrogen is making everyone ready. And my follicle is ready. I have crazy hormones going on. I'm feeling all nice and fluffy myself. All right, I think it's time to ovulate.