Long Contractions 38+3

38+3 weeks and have been having contractions (Braxton hicks) on and off since last night. Irregular. Nothing too intense. I just had an appointment 2 days ago my cervix was high, not dilated, and not softened yet. However I have been feeling very different since last night back pain/pressure/ cramping. My concern is that I have been attempting to time my Braxton hicks and I have noticed they are long lasting. The last one I timed was about 3 minutes. It didn’t hurt for the whole time but felt hard. Anyone else have these longer lasting contractions ?