During the second month of pregnancy, it is normal for a woman's heart rate to increase slightly. The average resting heart rate for pregnant women ranges from 80 to 90 beats per minute (bpm). However, every woman is different, and factors such as fitness level and overall health can affect heart rate. It is important to consult with a healthcare provider to determine what is considered normal for an individual pregnancy. If there are any concerns about a high or irregular heart rate, it is crucial to seek medical advice promptly.