The week two of pregnancy is all about making a baby. That's right - there's technically still no actual baby growing inside of you during week 2. It is during this week that you'll be copulating with a partner in hopes of becoming pregnant. That, or it was during this week you accidentally got knocked up. Either way, one thing is for sure: whatever sex you had during the second week of pregnancy was either free of birth control or was faulty birth control because guess what... it got you pregnant!
Week two of pregnancy is contraception week. It will take months before you know things like your baby's sex or eye color, but these details and so many others are already determined immediately upon contraception depending on what exact sperm cell inseminated your egg.
In the handful of days following contraception, your egg will transform from a solid grouping of cells to a clustered layer of cells around a fluid-filled cavity. This cavity is known as a blastocyst. The blastocyst will take a 7-10 day-long journey down the fallopian tubes into your uterus. And like that, you're pregnant!