is it possible to request a c-section?

Ch
im not pregnant yet, but i will be a FTM (apart from miscarriages). i was wondering if anyone has been able to schedule or request a c-section? i was on growth hormone treatment for a lot of my younger years, i was only 5lbs at birth. and even now im extremely petite... 5'-5'1 and 85lbs. im scared that i wont be able to give birth normally and something would happen to the baby. three years ago, i was 16+5 weeks and a high risk pregnancy when i lost my son. i think my body would have difficulty in childbirth, i wasnt far enough along in any of my pregnancies to find out how difficult it would be in the third trimester, yet alone giving birth. if anyone has any advice it would be hugely appreciated!