GBS question

So I got a call this morning from my doctors office saying that I came positive for GBS! I was in the hospital twice last week for contractions, the first they gave me shots to stop the contractions, the second time they spaced out on their own. The on call doctor told me to go back until they are 2 mins apart. My whole pregnancy I've seen the nurse practitioner, so when I saw her Monday she told me to go when I'm about 8-10 mins apart (which I did when I went to the hospital the two times and was sent home!) so I feel like her advice about timing isn't even valid since she isn't a doctor & wont be there when I give birth. when I had my daughter 4 years ago I was only in labor for THREE (3) hours & I didn't even start to feel the REAL pain until they broke my water. So HOW AM I SUPPOSED TO GET ANTIBIOTICS ON TIME???