Question

So me and my DH had sex tonight and I know that it is possible for that to make labor come. I am currently 37 weeks but was wondering about the low cramping. I dont want to waste time at the ER with contractions and cramps if they arent going to even exam me because we did have sex. Also for all the mommies that went into labor after having sex, how long did it take. I would love for my little boy to come but I know he will come when he is ready.