At which month do you start getting stretch mark?

alhamdulillah now dh 30w dekat perut xde stretch marks sbb sapu lotion palmer's cocoa dua kali sehari dri awl pregnancy.. tp dekat bwh breast baru perasan ade naik stretch marks. sedih nye lahai sbb tlepas pandang xpernah sapu lgsg.. jenuh laa nk hilang kn.