help gaining weight on pregnancy

hi! so a little back story i have 2 kids (2&4) and each pregnancy i lost a significant amount of weight postpartum. one kid i breastfed, the other i didnt. didnt change anything. i'm 22, 5'1 and probably 90lbs. i've been the same weight since i was 14. when i was pregnant i went up to 120 and postpartum i was like 110-105 and i LOVED the extra weight. i know 5-15 lbs doesn't seem like a lot but it was a lot for me. i felt it looked good on me. i tried eating good and working out to keep the weight on but unfortunately i ended up shedding it. i want to get pregnant again at either nov-dec 2025 or nov-dec 2026 (i want a summer baby). i've been doing a lot to try and get myself right, getting blood work, ultrasounds whatever i need to make sure im healthy. which the drs say nothing is wrong w me besides iron deficit and vitamin d deficit. i know it's just my genetics but i would love to not be an A cup anymore lol😂 and have some weight on my legs. when i had the extra weight i felt happy and i felt healthier and i had more energy.