Striped Linen Overalls

I am so bummed with this purchase (actually purchaseS since I reordered and tried sizing up) because the overalls are SO CUTE! I absolutely love the pattern and cut and would have definitely kept - if I wasn't pregnant. I initially purchased the small since med was sold out, our I would have heeded the reviews and ordered a medium from the get-go. The overalls were so tight on my (not too big) belly that the fabric was completely taught bordering on pulling. I returned and bought the medium when it became available and the medium was also way too small in the belly area. I was trying these on at the end of my 2nd trimester, so perhaps it's my fault for thinking a medium would be adequate. I didn't want to size up to a large for fear that the legs and chest area would be disproportionately large and the belly area might still be too tight. For reference: My pre-pregnancy wt was 118 lbs, 5'7, usually wear a size 25/0-2 in pants, XS/S in dresses... and at the time of trying on the overalls I was wearing a size S/2-4 in reg non-maternity loose dresses and weighed about 140 lbs.) I'm considering purchasing a small again after baby is born and wearing as regular overalls since they didn't seem like maternity overalls to me in any regard.