Labor contractions?

FTM here 38w1d today - I’ve had Braxton Hicks since about 25 weeks so I’m very familiar with them, but for the last 12 hours or so I’ve been having stronger contractions that feel like menstrual cramps and go into my back. They’re coming pretty regularly about every 2-3 minutes and lasting about 70 seconds, but they’re not so strong that I can’t talk or walk through them like my doctor said. Has anyone experienced this? I think i have a pretty average pain tolerance so I don’t think I’d be one to miss the “real deal” the way that everyone describes them. Do you think I should call the office or wait to see if they get stronger?