Help FTM..Not sure what to do.

Had Nst this morning the nurse that I have always had kept asking is he still as active. I told her yes but she kept rechecking me and asked it a couple more times. His heart beat sound slightly different this week. Also at the end when they let me go she said if anything seem off just go get checked without calling the dr. I have been havin a few brax hicks and been feeling more pressure in the lower region. When at lunch I had one and now my back will not stop hurting. I also have developed a headache and Tylenol is not helping. I'm a ftm and I'm not sure what to do. Do I go get checked or wait and see if things progress.