I'm too scared to spay my dog?

She is almost 6 years old. I have been so scared putting her under anesthesia. That was why I did not spay her sooner. However, recently she has been under anesthesia for tumor removal. She was fine, and now she is perfectly healthy. But I'm just too scared to put her into something involved anesthesia again, even though I know spay procedure is just a so common thing. She will be spayed this Friday, and I'm crossing my fingers hoping that there will no problem. Am I worried too much?