I have been pumping at work, but the other day I forgot a pump part so I bought a new Medela Harmony manual pump at the store (I have quite a long commute so going home was not an option). Since I was at work, I didn't have a way to boil the parts for 10 minutes before using them. I pumped twice: the first time into a new bottle that came with the kit, and the second time into a sanitized/washed bottle I had with me. I'd rather not throw away the EBM if I don't need to. So the question is, is there something that could harm the baby in the EBM if I didn't sanitize the parts out of the box, or is that more of a precaution? I know it's a long shot, but I was hoping someone could help that might have had a similar experience!