Pregnancy update 27 weeks

Well the past week has been so uncomfortable!! I made a trip to the ER last week to see what was going on but all that has done is make me worry. I was having some contractions but the nurse thought I might be dehydrated so I was sent home and told to aim for 64 ozs of non-decaffeinated drinks a day. I am trying to do this and I have been living in the bathroom lol! I am have pain on and off but mostly just uncomfortable. I have called my doctor's office and told them but they want me to just try to take it easy which I am and they will see me Aug. 4th. This is my 4th baby and I have never made it to 40 weeks my first was 6 weeks early and spent 2 months in NICU. Thank God he is healthy today but I do NOT want another baby to go through that! My 2nd baby was 3 weeks early but she was born healthy, and my 3rd baby was between 4-6 weeks early the doctor's argued over how early they thought he was because he weighed almost 6lbs he had to stay a few extra days in the hospital because his oxygen level was low. So I have never had any problems this early and it is really stressing me which I know can make matters worse. I just want the doctor to understand and take my concerns seriously. I would feel better if they check my cervix to make sure I haven't dilated maybe that would ease my mind somewhat.