What's the deal with lubricant?

This study shows it made no difference. I accidentally used it the last few months. This month I had what I think might be implantation bleeding but now I just learned it can kill sperm... Needless to say I'm discouraged now.
http://www.foxnews.com/health/2012/07/11/lubricants-may-not-harm-fertility.html
Thoughts? Experiences?