thawed milk smell?

thankthesox

i've been paranoid that my baby's tummy is way worse when i use thawed milk & worried it's not good... it doesn't smell sour but it has this weird almost plasticky smell - is this normal?  or should thawed milk smell the same as fresh?  it may just be a coincidence but it seems like days i've used milk that was frozen while my baby was in the NICU happen to be days she's had really bad stomach issues.