Tonsillitis =antibiotics??

Hi All, I'm 6 months out from a hip replacement and have just got the worst sore throat I've ever had with problems of swallowing etc and I'm concerned it's a bacterial infection.

I'll definitely try and get hold of the hospital where I had my operation, but the only way I'll know if it's a bacterial infection and therefore correct to take the antibiotics is if they take a swab etc and that will take time (it's weekend of course).

Has anyone had a similar issue?

I do already have a box of the correct antibiotics from my surgeon (in case I get an infection while scuba diving in remote areas), so I'm wondering if I just take them?? If it's a viral infection then I'm taking them for nothing but if it's a bacterial infection.... Thanks!