Your baby is a fertilized egg (also known as a blastocyst) that is implanting in your uterus this week. The blastocyst has split into two layers of cells, called the epiblast and the hypoblast. The epiblast will develop and split into the placenta and the baby; while the hypoblast orients the epiblast so it develops symmetrically, and also develops into the yolk sac, which will sustain the baby until the placenta takes over.
You may not have any pregnancy symptoms yet, but since the fertilized egg is growing, some pregnancy hormones are already starting to be produced. If you've been trying to conceive for a while, or you've been tracking your ovulation, you may be hyper-aware of pregnancy symptoms.
Many of the earliest pregnancy symptoms are similar to PMS symptoms, so it can be hard to tell what you're experiencing. Often, a missed period is the first unambiguous sign that you may be pregnant.
Lower Abdominal Pressure - some people report pressure or cramping when the fertilized egg implants.
Metallic Taste - hormones can cause a metallic taste in your mouth, or cause foods to taste differently. This may be something you're used to from PMS, or it might be an unfortunate new experience. Some sources recommend drinking or eating acidic things if it gets unbearable.
Implantation Bleeding - fewer than 25% of people report a slight amount of bleeding during implantation. If you don't know you're pregnant, this can be mistaken for your period. If you're hoping you're pregnant, this can be scary and sad since it occurs when you'd expect your period. If you're in the latter camp, you can refer to our miscarriage page for advice and reassurance.