Don't worry about calling them to ask any questions you may have. During the first trimester, the babies heart will start to beat at around 25 days, although you will not be able to hear it until around 8-12 weeks. The chances of a miscarriage after you hear the heart beat usually becomes very slim. Many couples wait until after this milestone before telling family and friends about an expecting pregnancy for this reason. The heart beat can usually be heard between 10 and 20 weeks, and at every visit to the OB or midwife from then on.
Folic acid is very important in brain development, and in preventing birth defects.
The brain doesn't stop developing after the first trimester, but now is a great time to get used to reading and talking to your baby. The first half of the pregnancy is the most crucial to the development. Your baby is also sprouting out little arms, legs and has very underdeveloped and immature organs. And somewhere around the 13th week it will have developed male or female reproductive organs, although you will not be able to see them usually until at least the second trimester ultrasound. At about 8 weeks, the fetus will begin to develope hair finger nails, toe nails, and bud for the distant future teeth also start to form.