For me, first trimester was filled of all sorts of emotions: exhaustion, anxiety, queasiness, and almost flu-like symptoms. All the sudden, you may question everything you eat and do. I found Babycenter to be a great resource, as long as you don't get trapped in the message boards--everyone's input is just confusing and will really freak you out! Some of my worst weeks were also complicated by the fact that I was on a surgery rotation that was exhausting in and of itself. Below are some things that helped me get through.
A) Larabars are a quick and easy, semi-healthy, semi-paleo snack. With all the food and smell aversions in my first trimester, having something easy that actually sounds appealing is so important.
B) Belli skincare products. Pretty much all acne products are off-limits during pregnancy, but I felt safe using these since they are designed specifically for pregnant women. I am still using the Pre-treatment scrub and Acne spot treatment, and really like them.
C) A good Tervis or water bottle. Staying hydrated is so, so important when you may be nauseated and not able to eat much.
D) The Snoogle! Basically an adult Boppy, this pillow has helped get me used to sleeping on my side.
E) I would highly suggest putting away all your tight fitting clothes during the first trimester. With all the bloating, good peplum or flowy tops will make you feel much less self-conscious. (Even though no one else can even tell you aren't having the flattest of stomach days).
F) For all the CrossFitters out there, this website is fantastic. It has stood the test of time and has thousands of mom-to-be followers. It has the most straight forward recommendations on dos and donts during each trimester of pregnancy that I could find anywhere. I did not feel comfortable going back to CrossFit class until the end of my first trimester, and CrossFit Mom's daily workouts were great (although I was only managing to do 2, maybe 3 a week). I also want to throw it out there that pregnancy has really made exercise much tougher on me. My pulse will sky rocket after doing anything and I feel much more winded, so I have taken the intensity down greatly. I think keeping in mind that your heart is now pumping enough blood for two and giving yourself some slack is important. Just do whatever activity you can! I happen to love CrossFit, and feel so lucky that I have been able to continue so far.