Five Weeks!

Week 5: The embryonic period begins

The fifth week of pregnancy, or the third week after conception, marks the beginning of the embryonic period. This is when the baby's brain, spinal cord, heart and other organs begin to form.

The embryo is now made of three layers. The top layer — the ectoderm — will give rise to your baby's outermost layer of skin, central and peripheral nervous systems, eyes, inner ear, and many connective tissues.

Your baby's heart and a primitive circulatory system will form in the middle layer of cells — the mesoderm. This layer of cells will also serve as the foundation for your baby's bones, muscles, kidneys and much of the reproductive system.

The inner layer of cells — the endoderm — will become a simple tube lined with mucous membranes. Your baby's lungs, intestines and bladder will develop here.

By the end of this week, your baby is likely about the size of the tip of a pen.
Source

A lil' update. I went and had what I had hoped was my final beta (blood draw) yesterday. I was 20 dpo and though I doubted I'd have a number of 2,000+, I went in anyway. The nurse insisted last week that I needed 2,000+ before the OB would submit the order for an ultrasound. So, I went in, came home to find an email from my OB stating she put in an order for an ultrasound already. YAY! I went to schedule that, but they are booked and will call me sometime in the next week and a half, maybe the morning of the 8th. They sounded sort of wishy washy, but I just let it go.

I found out my number for 20 dpo, and I was expecting 1100-1500 maybe. Well, the nurse told me and I started shaking - 2,744. I was just NOT expecting anything in the two thousand range, yet! I am still in disbelief, with the number, with the fact that I am really pregnant again. I feel so blessed, I just sit here and think about it and I get teary eyed.. I'm incredibly lucky. :D