Braxton Hicks/Preterm Labor

I am 32 weeks and I am having significant lower back/side pain and cramps (for a few weeks now). I know this is a sign of preterm labor but it comes and goes without any normal interval. Sometimes in the morning, middle of the night or during the day. Also, it does not go away with position change or water like Braxton Hicks contractions are supposed to. What would you say this is or have you experienced this before??