I think I experienced some early braxton hicks this moring on my walk to work.
My tummy went rock hard and I felt cramping in my uterus.
'Sometime towards the middle of your pregnancy (or even earlier), you may notice the muscles of your uterus (womb) tightening, for anywhere from 30 to 60 seconds. This may happen to you several times an hour, several times a day (Cheng et al 2006).
Not all of us feel these random, usually painless contractions, which get their name from John Braxton Hicks, an English doctor who first described them in 1872.
Experts have different opinions about Braxton Hicks contractions and their true purpose. Some believe that they play a part in getting your cervix ready for labour (also called "ripening") (Walsh 2004:430).
Others believe that Braxton Hicks contractions do not lead to changes to the cervix and that ripening only occurs in pre-labour, when the first co-ordinated contractions of labour start (Murray 2003:187; Baker 2006:53) or in labour itself (Cheng et al 2006).' babycentre.co.uk