Braxton Hicks question!

Andrea • I'm a mommy to a 3 year old daughter named Juliet and a newborn named Laila born October 16th 2017! I am blessed.
I'm 21+5 weeks pregnant with my 2nd baby. In my first pregnancy I dont recall having any Braxton Hicks contractions, but I am really curious this time around... how early have some of you lovely ladies had these contractions? Did anything in particular bring them about? How long did they last?