Do not take any over the counter antibiotics without consulting your OBGY specialist.
Recurrent UTI will not affect your baby and can be because of the enlarged uterus pressing against the bladder, leading to stasis of urinary flow.
Also, penicillins, cephalosporins and macrolide antibiotics are safe in pregnancy. Amoxycillin is a broad spectrum penicillin. They may not harm the Baby directly, but can impact your health which can further harm the Baby.
Next Steps
do not take OTC drugs without consulting Dr.