I spoke to normal GP who left script for me to pick up Sat when I was to start clear liquids for 3 day... I missed surgery closing Sat morning so went to local GP and given CILEX ( cephalexin) . I didn't want to lose th chance ot start liquid diet. Anyway I went Monday and picked up normal GP's script and it was for Clavycillin 875/125. Can I just stop one and start another. I have had cephalexin for 2 days and 1 morning dose 3rd day?