Preterm labor!??

FTM.. 31 weeks. I’ve had Braxton hicks for a while now. Just tightening but no pain. Last night after my 12 hour shift (RN) I starting having very painful contractions. They quickly picked up to every 2-3 min and then spread out to 4-6 min for about 4 hours. Kept causing me to have diarrhea due to all the pressure. I didn’t go in, but the is morning my OB said I should have and that if they start back up I need to come in. I’m having 1-3 ctx an hour today. Some are painful/lots of pressure and some aren’t. I just feel icky too- no appetite. Did anyone have preterm labor or even labor in general that started like this? We are in a wedding tomorrow and I’m just wondering how likely it is that they pick back up and I need to go in. I’m a ftm, but had a miscarriage last year and last night felt close to the horrible cramps/ ctx when I was passing my miscarriage. Thanks in advance