If im 31 weeks and have had pains like contractions, is it braxton hicks?

Maybe: Braxton hicks contractions are false labor pains. Most people find them to be a painless tightening over the whole uterus. Real contractions are uncomfortable to painful, are usually low across the abdomen, can be associated with spotting or increase in vaginal discharge. Because you are 31 weeks it is very important to distinguish between the two. I would recommend you call your doctor.