I found these two deviantart authors who do really great stories about pregnancy where the weight gain is mainly focused on making the babies bigger with a side focus on their body, breast expansion and lactation.
Hyperpregnancy this author has a few good oneshots but their main one is a continuing story called [Hyperpregnancy] Quintuplets and Growing part1 2 3 4 5 6 7 8 9 10 which also has a quadruplet pregnancy progression.
Also [Rapid Pregnancy] Two Years in Three Days part 1, [Rapid Pregnancy] More Than She Bargained For, [Hyperpregnancy] The Ultrasound, [Rapid Pregnancy] The Wishmaster
gravidliv This author also has good stories Liv's Plentiful Motherhood pt. 1 2 3, Liv at the Baby Factory, The Swollen Sisterhood 1-2, Contributing to Society 1-2, The Milkmaidens' Farm, Breeder Streamer, The Appendage 1 2 3 and Liv's Tentacle Lover
Hyperpregnancy this author has a few good oneshots but their main one is a continuing story called [Hyperpregnancy] Quintuplets and Growing part1 2 3 4 5 6 7 8 9 10 which also has a quadruplet pregnancy progression.
Also [Rapid Pregnancy] Two Years in Three Days part 1, [Rapid Pregnancy] More Than She Bargained For, [Hyperpregnancy] The Ultrasound, [Rapid Pregnancy] The Wishmaster
gravidliv This author also has good stories Liv's Plentiful Motherhood pt. 1 2 3, Liv at the Baby Factory, The Swollen Sisterhood 1-2, Contributing to Society 1-2, The Milkmaidens' Farm, Breeder Streamer, The Appendage 1 2 3 and Liv's Tentacle Lover
