Hi Juliaho90, whilst it is best to ask at the clinic about the interaction between all your medications, current research seems to indicate that amoxicillin, and most other common antibiotics don't interact with birth control for
most people. You can read more about this here:
Something You Can Worry About Less: Interference and Hormonal Birth Control. If the illness you are treating with the antibiotics is causing you to vomit or have diarrhea, your body may not absorb your pill completely, so you should use a backup method during and for at least one week after your symptoms subside.
If you want to be extra safe, you can use a condom as backup whilst taking the antibiotics and for a week after (which from your previous posts you already do, so continue to do that). This also helps as if your body is fighting an infection, as during this time your body is more susceptible to STIs.