I had braxton-hicks early in all of my pregnancies. I never knew what they were (with my 1st preg.) until I went to lamaze class. I always thought the baby was in a "ball" as opposed to all stretched out. (lol. I was young!) But it's perfectly normal. Or at least, it doesn't mean anything is wrong and you're going to loose the baby. Later in my pregnancies, my braxton-hicks were "on-time." They would start, or I would notice them when they were 15 mins apart and slowly they would get 1-2 mins apart. But nothing ever happened. I was observed in the hospital over and over and over, but nothing ever came of those episodes. They just pumped me full of IV fluids and eventually they would stop.
Just try not to worry, easier said than done, but stress is the last thing you need right now.