Stretchmark on butt and thighs

Im currently 34weeks++, im petite but my bump os quite big. Ive been using bio oil + palmer’s lotion religiously twice a day since 1st trim, however ive started to notice overnight @34w suddenly stretchmarks starts to appear here and there 😭 Stretch mark on belly is common as the skin is stretching however i also have on my tight butt cheeks and both thighs. As far as i know my butt and thigh is still the same size as before and doesnt expand but how come theres stretchmarks there ? Its the red/purple ones 😭 Is it common to have stretch marks on butt cheeks and side of both thighs ?? Will it ever fade post delivery if i continue using the stretch mark lotion ? #FTM