Is it safe to take antibiotics while pregnant?

Yes. While some antibiotics are not safe in pregnancy, you can be assured your OB would not prescribe unsafe antibiotics during your pregnancy. It's important to complete all prescribed antibiotics.
Many are. Some antibiotics are safe in pregnancy. Others need to be avoided at certain times. Talk to you doctor and make sure they know you are pregnant with any new prescription.
Antibiotics. Yes generally. Please check with your obgyn and be sure that the issue you want to treat with antibiotics is treatable with antibiotic therapy (they work on bacterial infections but not on viral infections like colds/flu).