Is Antibiotic Injection Advisable For Ear Infection During Pregnancy?

I m nine months pregnant and I have an ear infection, I need an antibiotic and the Dr proscribed an injection to take twice once every 24 hours. Is that safe? When I asked my OBGYN she preferred a different antibiotic! What should I do? I m not in the US and drs here proscribe medicine and if anything goes wrong there are really no liability consequences.