What Causes Loss Of Memory?

I am having a great deal of problem with my memory. I am a 42 year old female in good health and my memory seems to be getting worse. I know forgetting days and names is normal, however, I am forgetting things that I have done repeatedly. One example, about six months ago I switched my hot pan holder and kitchen towel drawers in my kitchen and I can never remember which drawer has which in it. There is a shift key and an alt key on my phone, one makes capital letters and the other makes punctuation marks, I can t remember which is which. I don t remember jokes or things that were told just a short time before. My children get mad at me because I ask them a question, they answer it and I forget that I even asked and ask them several times more. I find myself repeating myself often. Is there anything to be concerned about or is this level of memory loss normal?