Severe Bladder Infection?

Well a little background, I am 30 weeks and I went to L&D on Monday due to decreased fetal movement and I told the nurse that I was experiencing symptoms of a UTI as well. She never took a urine sample, but I had a low grade fever (99.9) and my BP was elevated (143/93) she said I was fine and sent me home. Well over the course of this week, the back pain and the burning sensation has gotten worse. I went in for my weekly NST and OB visit today and I mentioned my discomfort to the nurse and she checked my urine. My OB came in and checked my NST chart and said that I had had 3 contractions within the 20 minutes that I was being monitired and that they found blood in my urine. He prescribed me Macrobid and also told me to take some over the counter AZO. I have had the contractions all day, I am nauseous, still have the back pain and now I have diarrhea. He told me that if I wasnt feeling any better in 2-3 days to let him know as it could spread to my kidneys. Now my question to you is, how uncomfortable is uncomfortable enough to go to the ER? I am worried about pre-term labor as I am a high risk pregnancy. Thanks in advance!