Be sure that you only accept and use antibiotics from your doctor if they are sure you are having a bacterial infection.
Up to 97% of coughs, colds and "flu" are caused by viruses and do not respond to antibiotics.
At most, they may make you feel better by
1) exerting an anti-inflammatory effect similar to that of taking a Paracetamol.
2) making you think the antibiotics are working when actually the natural progression of a cold is simply to get better by day 3 or day 4.
Examples of bacterial infections include Otitis Media, Acute bacterial tonsillitis, Urinary tract infections.
They DO NOT work on viruses.
Yes, bacterial infections can complicate a cold, but this usually only happens around day 5-7 of the illness. There is no magic predictor of this, and a doctor will always have to make a re-assessment at that point in time.
Do you really want to ruin the precious gut microbiome you spent all your life culturing, by using antibiotics for no good reason?
Watch this video to see with your own eyes how antibiotic resistance occurs.