So when I had kidney stone pains back around 28 weeks I thought I was having lightening crotch because of the random pains I was having down low. When i was being monitored in labor and delivery while at hospital those feelings ended up being contractions that weren't regular so nurses and OB wasnt concerned. I wasn't able to tell they were contractions. Well I have been having those feelings again past few days. I'm 35 weeks and 3 days. How do I tell the difference between lightening crotch and early contractions?