crying over nothing

So the other day I was cooking for my other children I have and in the process I didn't realize there was a drop of milk left when I needed 2 cups for the food.. When my mom came out and told me there was no milk I started crying lol she said it's ok I'll go get more don't worry and I was still crying my kids came out and said what's wrong mommy and I said there's no milk they looked at me like what the hell? Lol I had to explain to them sometimes pregnant women cry for no reason lol