Pain @ 35

It's my 35th week of preg today but last night, halos magdamag aqong gising kasi medyo masakit ang tyan at lower back q at hanggang ngayon ganon pa din (pasumpong2. Di naman sobrang sakit at hindi lumalakas yung pain pero bakit ganon? Naranasan q ang braxton pero bakit mas madalis ito at may pain? Is it normal? Ayokong magpreterm...