Membrane sweep 38+5

Pregnant with baby number 4 and have never gone into labor on my own..kinda scared to honestly but just curious if any of you ladies have had one done and how it went? Did you have to be a certain amount dilated? I will be 38+5 durimg my appt and want to ask my doc about it but just curious n bored so thought id post it on here 😄 thanx ladies!