I had a tubal litigation and now I have an infection. I am on my 2nd antibiotic.?

I am 4 days into the antibiotic. How long will it take for me to start feeling better and have less pain? If this antibiotic doesn't work they are talking about putting me into the hospital on antibiotic IV. And if that doesn't work he said we may have to do a hysterectomy. So I just want to know when I should call the doc. if I am not feeling better.