jump into a hot bath/shower for abit and see if that settles them, if not then they maybe real contractions, sometimes in the latter stages of pregnancy b/h can get quite painful and can be confused with early contractions, but if your having to stop what your doing and concentrate on them, then they maybe the real deal....
If I walk for a while, I get painful braxton Hicks. They can range from not painful at all, to feeling like a real contraction.