A: Congratulations on your pregnancy! Hearing the heartbeat should be very reassuring. It's a sign that your baby is developing nicely.

It takes nine months to grow a baby, and nine months for your breasts to prepare for lactation. Inside your breasts is a network of branching milk ducts that lead to alveoli, small balloon-like structures that will eventually make and store breast milk. The hormones primarily involved in breast growth include estrogen and progesterone. As your pregnancy proceeds, these hormones will rise. Estrogen stimulates the growth and branching of breast ducts, while progesterone promotes growth and development of the alveoli.

What's important for you to know is that your breasts will gradually grow in size over the course of the pregnancy. There are certainly changes happening within your breasts at this moment, but they may or not be noticeable. Every woman is a bit different in her own experience, but a lack of obvious breast growth at 14 weeks is entirely normal. The increase in breast size that will undoubtedly occur may not be evident until the last weeks of pregnancy. During the first trimester, your growing uterus and the sound of your baby's heartbeat are the best indications of your baby's well being.