Labor?

So I am a second time mom, been pregnant two years in a row, my son is almost 14mo and I am 38 weeks pregnant and some days....

With my son, I was able to see my contractions happening, I could feel when one was about to start, see and feel the releasing....

For the last 2 hours, I've been having this tightening and I can barely feel it starting, I just feel like it's so abrupt....and I can't see tightening...I think I do but then I'm like wait what if it's just my pulse? Ya know?

Did anyone have a different contraction experience with your second baby?