I have used the cup many times for just that reason. When my husband planned a wonderful, romantic getaway for us last summer. I was a little upset with him because he did not take into account the fact that I would be on my period. My cycle is so regular that I was sure he would think about that. Duh! Anyway my best friend told me about the cup an it was wonderful. I used it according to the package directions and had absolutely no problems. My husband had no idea. The really funny part was a week later he is acting very nervous and when I asked him what was up he shared that he had just realized that I had skipped a period and wanted to know if I could be pregnant.
Not hardly since I am 43.