What is the percentage of getting pregnant if on the pill and taking amoxicillin and no other protection??

Antibiotics make the pill ineffective, so your chances of getting pregnant are the same as if you were not using birth control. If you are taking antibiotics, use a condom.

It depends on what information source you look at. Newer research suggests most antibiotics will not have an effect on the benefits of the pill as was once thought.

Some feel they may decrease the effectiveness and it would be wise to use back up birth control while on the antibiotic to be on the safe side.

There have been no studies to really give a definitive answer as to the percentage that might become pregnant while using both.

Trust me... You should really use back up.