What should i be aware of

Hello moms, im having my 4th child due july 28th, i have had c sections for all 3, never dilated past 1 and never felt true contractions... for some reason i just have a gut feeling my lil man will be comming early. Never felt this with any of my others. Im 33 weeks and he is sitting so low head in my pelvis (very painful) and having more and more braxton hick contractions and pain like my c section scar is being pulled apart to the point of me crying.... i guess what im asking is what would be signs to watch for, for pre term labor of him comming before c section?