Are pelvic exams safe? 18 weeks

I had a minor car accident last night. Went to hospital to get baby checked. Hospital doc did a cervix check to make sure I wasn't dialated. I read online that this can lead to infections of amniotic sac due to "pushing" more bacteria up the vagina.  Needless to say I am freaking out and regretting letting her do it. I'm almost 18 weeks. Is there anything I can do now or just wait it out.