She had a blood test done, I'm not sure if a culture was done. Is a culture more accurate than blood?

Yes, blood tests for infections are antibody tests, which are VERY inaccurate.

I can understand what you mean though. Is ciproflaxin and docyclenin effective in treating infections?

Depends on the infection. They may work if it is a bacterial infection but not for viral or fungal infections.

I work with a fellow that says antibiotics are very harmful.

They are damaging to the immune system and can lead to secondary infections.