Believe it or not, Braxton Hicks contractions can start as early as six weeks into your pregnancy! You will not feel them immediately though, as your uterus (and your baby) is still tiny and tucked safely into your abdominal cavity. After you are about half way through your second trimester of pregnancy, your baby will have grown a lot and your uterus will have reached your belly button. It is at around this time that Braxton Hicks contractions start becoming noticeable. Apparently, there are some expectant moms who never notice Braxton Hicks Contractions, but I have never personally met any of them, and I think this is a very rare occurrence.
As you go into your third trimester, you are likely to be experiencing a whole lot more "practice contractions". It is hardly surprising that these contractions are also simply known as "hard tummies" in some languages, because that is exactly what they do to you. When will you get Braxton Hicks contractions? Many women notice an increase when they are really physically active, lift heavy things, have sexual intercourse, or an orgasm. Braxton Hicks contractions do have a tendency to end quickly, and often clear up when you change positions. Try sitting down if you were standing, or rolling over to a different side during the night.