Braxton Hicks vs Preterm Labor

Gabby.
Alright momma's. I feel so uneducated even though I'm not a FTM. I'm currently 33w5d. I had preterm labor complications with my daughter starting at 30wks and actually delivered her early, but it's been six years since I've gone through all of that so I really just don't fully remember how it all began as far as when the contractions started and got worse. I also never experienced Braxton hicks when I was pregnant with her, so I don't know what they feel those should really feel like.
I've been having what I would assume is Braxton hicks contractions since last night. It all started in my back, and then it became my back radiating into my sides and belly. I was up and down out of bed all night. Since I've woke this morning, the back pain has become dull and no longer sharp, but the pain in my pelvic area and full tightening of my whole stomach has become stronger and more persistent. The timing of them isn't 100% consistent, but it's coming every 4-6 minutes.
Are these just BH? Did they start as BH and now progressing? When do you cross the line from BH to contractions to the point of needing to be checked. I'm easily having 10-15 in an hour. I just am so hesitant about going to be checked because I still feel baby moving and they aren't super strong. I'm good and hydrated, I drink easily 70 oz a day, but have been pushing even more since the weather here has gotten hot to the point I think I'm officially peeing out straight water. Any advice, thoughts, opinions? My doc is out of town for another two days so my only option would be going to the hospital if I need to be checked.