From babycenter.com:
Baby is now made up of three layers — the ectoderm, the mesoderm, and the endoderm — which will later form all of his/her organs and tissues.
The neural tube — from which baby's brain, spinal cord, nerves, and backbone will sprout — is starting to develop in the top layer, called the ectoderm. This layer will also give rise to his/her skin, hair, nails, mammary and sweat glands, and tooth enamel.
His/her heart and circulatory system begin to form in the middle layer, or mesoderm. (This week, in fact, his/her tiny heart begins to divide into chambers and beat and pump blood.) The mesoderm will also form baby's muscles, cartilage, bone, and subcutaneous (under skin) tissue.
The third layer, or endoderm, will house his/her lungs, intestines, and rudimentary urinary system, as well as thyroid, liver, and pancreas. In the meantime, the primitive placenta and umbilical cord, which deliver nourishment and oxygen to baby, are already on the job.
I haven't noticed any new symptoms yet (except, on a unrelated note, I tweaked something in my neck yesterday and it's been killing me the last two days. And although I can take Tylenol, I'm trying to be as natural as possible in this first trimester).
I'm working on improving my diet (switching to decaf coffee wasn't hard until today) and drinking LOTS of water.
My physician said I could continue exercising at my current level as tolerated and not to fatigue, but Matt and I decided it was best if I find a replacement for my spot on our Cascade Lakes Relay team (it would've been my 3rd year in this race-- the race in which Matt & I met in 2010. Now he has to do it without me :( but it'll be his 5th year!). I intentionally picked easy 3-mile legs (three total) in case I got pregnant, or failed to amp up my training. Hopefully that'll make it seem enticing to someone who will join last minute. I ran for the first time on Saturday on my favorite trail, but I decided to just take it REALLY easy just in case. It was in the 90's that afternoon so I walked up all the hills. Slowest run ever, I ran an average of 11:30/mile. Geez. Baby better appreciate that ;) My legs were a bit sore since I've barely done anything in weeks, what with all my travel earlier, but it still felt great on the heart and lungs. I told Matt that I'm sure Baby enjoyed the run too.
Matt's really enjoying the babycenter app on our iPhones that gives lots of pregnancy tips and a checklist. He's being super supportive and seeing how excited and involved he is gives me confidence :)
We have our first OB appointment on July 24th, which seems like forever away. I'm hoping they at least let us hear the baby's heartbeat.
