lightening crotch??

Thalia • Baby #2🤗
Im 31 weeks and yesterday i was having a strong pain for a couple of seconds on my vaginal area while walking and ive been told its lightening crotch and contractions. This is my first baby so im not sure what contractions feel like is lightening crotch part of contractions??? Btw babygirl in a transverse position i dont feel her head down.