Amoxicillin is a penicillin-type antibiotic that is widely used during pregnancy and breastfeeding because it has a long safety record. Doctors often choose penicillin-family antibiotics for pregnant and breastfeeding patients when an antibiotic is genuinely needed.
Antibiotics are only helpful for bacterial infections, not viral ones like most colds, so they should be taken only when a clinician decides they are appropriate. Taking unneeded antibiotics carries its own risks, including resistance and side effects.
If you are allergic to penicillin, tell your doctor so a suitable alternative can be chosen. Finish the full course as directed, and report any rash, breathing difficulty, or severe diarrhoea promptly. While breastfeeding, watch for thrush or loose stools in your baby and mention them to your provider.