Braxton Hicks contractions can start as early as the second trimester of pregnancy, sometimes even around 16 to 20 weeks, but they are most commonly felt in the third trimester. The uterus may begin these rehearsal contractions as early as 6 weeks, but they are usually not felt at that early stage. Most women notice them from around 20 weeks onward, with frequency increasing as the pregnancy progresses, especially in the ninth month. These contractions are irregular, usually short (about 30 seconds), and typically not painful—they serve as the body's way of preparing for labor without causing cervical dilation.
In summary, Braxton Hicks contractions can be felt as early as the second trimester, commonly starting from about 16 to 20 weeks, but they become more frequent and noticeable closer to the due date.
