milk question...

I have a question about milk. I've read about the testing that you've done on milk, but still confused by dates, etc, and when the first actual levels of radiation first started showing up. I'm in the state of WA and purchased Costco milk on 3/17. When I contacted Costco, the buyer told me that the milk I purchased was made on the 1st of March. I questioned this, but they do have a very long shelf life and the buyer said she was confident. Anyway, I've gone back and forth over this issue in my mind, and even "if" they are wrong about when my milk was actually made, I figure the milk would still have been made days before the 17th. But can anyone be certain when radiation first affected milk? I've read that the first traces were found on the 25th, but could it have been sooner?

I guess I'm torn between giving my kids the last milk we have, and throwing it away just to be on the safe side. Any thoughts to help my decision? Sorry for sounding crazy, but I shoulder all of the responsibility in my house when it comes to my kids. My husband is completely opposite of me when it comes to this radiation issue. He thinks I'm worried too much, and I think you can't worry enough when it comes to our children. And while I've rationalized it in my head more than once, I've come to the conclusion that I can't make an informed decision with all of the info out there. It's too overwhelming.

Any advice would be helpful. Thank you!