So Im 31 weeks and my water broke at work

went to the hospital and was dialated at a 1 with contractions every 2 to 4 minutes. They now have me on hospital bed rest until he is born. I was given magnesium to stop the contractions I'm on my third bag now. I was just wondering if anyone else has been in a similar situation and if so how long after being off magnesium did the contractions start again? I'm just scared they're gonna start as soon as they take me off!
Re: Early labor,, magnesium??
Mommy to 5, 1st time Gestational Carrier
Transfers #1-4 2013/2014 all same DE, all CP
Transfer #5 11/16/14, new DE, transferred two fresh 5-day blasts
Beta 9dp5dt - 296 Beta 15dp5dt - 6,596! TWINS!! due 8/4/15
Admitted to hospital for preterm labor and 5cm dilated at 32 + 6
Delivered healthy baby girls vaginally at 36 + 4
Baby A 6lb10oz born at 11:58pm
Baby B 6lb11oz born at 12:04am
(different birthdays!)