If you are feeling really uncomfortable with it...2 options: dr might need to
1. change to an alternate antibiotic or
2. take the same antibiotics but take with an antisickness (anti nausea) medication.
When you called the clinic, did you speak to the dr or the nurse? Better to speak to the dr directly or to go back to the clinic.

It's a really common side effect for antibiotics... nausea and stomach upset or even diarrhoea... if can tahan continue as long as you dont vomit it out... if really uncomfortable then do the above.