Please help

I have been using Dr Brown's feeding bottles, purple 8 oz plastic bottles for my baby, purchased from Amazon. Previously, I purchased clear 5 oz bottles and they were made in USA. I never realized to check these 8oz purple pack manufacturer. Lately, while I was washing these bottles, I saw on the bottom of bottle they were Made in China. Now, I am worried if these bottles are real dr browns, if the material is same as those made in USA. I really feel guilty for this. Anyone using Made in China feeding bottles and do you think these are fine? Please help. Thanks