H&M Mama Before/After Cotton Pajamas, Maternity Women's Size Small, Red Hearts

Bought recently but need a bigger size! I usually wear a size small but would prefer these larger. Measured in-seam at 27.5" and length from bottom curve of neckline to bottom of shirt at 20". Fragrance free detergent, pet and smoke free home. From H&M: Pajamas in soft cotton jersey with a T-shirt and pants, both with a printed design. T-shirt with a crew neck, dropped shoulders, and elbow-length sleeves. Pants with a low waist and elasticized waistband. For wear during and after pregnancy.