For me with my first, my contractions fw lt like period cramps...they just got to be super painful and close together. What I would recommend is if you do start having cramping to get a pen and piece of papet and write down the time every time you have a contraction and if thwy start to get consistant (I believe 3-4 minutes apart if I remember correctly) I would maybe either call your doctor (if they have an on-call number for you to call after hours) or go to the er. I had my membranes stripped 2 or 3 times befor I actually went into labor. And when I did go into labor it was 2 days after the last membrane strip
Had it done several times as well before anything happened it's ultimately up to lil one when your going to go into labor you know unless you have c section well best of luck mommy and congratulations