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Your Pregnancy Journey in 3D Ultrasound: What’s Happening at 3 Weeks?

Writer: A.S, RDMSA.S, RDMS

Updated: Feb 28

At 3 weeks pregnant, fertilization happens—this is the official start of your baby’s journey! 🎉

3D Ultrasound at 3 Weeks

  • It’s too early to see a gestational sac, yolk sac or an embryo on an ultrasound, but big changes are happening inside!

  • By week 4-5, a gestational sac may become visible.


What’s Happening?

  • The sperm meets the egg in the fallopian tube, creating a tiny zygote (fertilized egg).


Sperm penetrating human egg
  • The zygote starts dividing into more cells as it travels to the uterus.

  • By the end of this week, it becomes a blastocyst and prepares to implant into the uterine lining.


    Fertilization and embryonic development
    Fertilization and embryonic development

Your Body’s Changes

  • You may not feel pregnant yet, but your body is already releasing hormones to support the pregnancy.

  • Some women experience implantation spotting (a light pink or brown discharge) when the blastocyst attaches to the uterus.


 
 
 

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