Lightning crotch?!

Ashley • I'm 23. my son is 2 yrs old. And my bf is 24 We've been together for 8yrs in sept. Expecting our baby girl April 14 !!
Anyone else experiencing lightning crotch ? Tonight it's happening pretty frequently. At any point should I be concerned ? I'm 37 weeks as of today and Monday my dr said I was thin and 1cm.