I’m worried

I know this is so silly to think about but I’m very self conscious about this. So this is mi 2 pregnancy I’m 3 weeks and I’m so scared I will get stretch marks,with my first pregnancy I got them but just a little on my lower abdomen and they are not noticeable at all I was 17 when I had my daughter and I was 18 and very skinny now I’m 25 still the same body type. What do you guys suggest?