Is it safe to have sex 3 weeks after c-section and tubal ligation?

Questionable: It is "safe" in the sense that you probably wont become pregnant from the experience:-) Could cause some pain and possibly an ascending infection in the uterus. Sex happens frequently but the infection risk is rare. However, I do think the risk benefit ratio falls in favor of abstinence till after 4 weeks minimum and 6 weeks preferably.