9 weeks pregnant stomach stretch marks especially light may be related to individual differences, generally normal. The formation of stretch marks is mainly related to the imbalance between estrogen and androgen secretion during pregnancy, which deepens the pigmentation and aggravates the pigmentation, resulting in pigmentation of the underlying skin, most of which are formed between the 2nd and 4th trimester of pregnancy, but there are certain individual differences in the length and depth of the stretch marks of each pregnant woman, and some pregnant women may also appear to have stretch marks that are not obvious, which are all normal. The reason for the formation of stretch marks is actually a pregnancy reaction, usually more hairy or more pigmented people, stretch marks are more obvious, which is not directly related to the growth and development of the baby, and most people will gradually disappear on their own after delivery.