I'm breastfeeding my 1.5 months baby. I want to give him Lactogen once in week (when I take head bath or go to hospital for sometime). Once Lactogen box is opened, it should be consumed within 3 weeks it seems. But its not possible for me to give so much of Lactogen. Can I still use the same Lactogen box after 3 weeks since shelf life is 12 months. Please suggest.