START TAKING THEM NOW! You will be sooooo much better off taking them! I have the same problem with a very sensitive stomach. It is a VERY safe and very effective drug. Doctors are VERY careful who they give antibiotics to. If they were prescribed you need to take them NOW! Get yourself in the mindset that if you eat first, you will not get sick! Otherwise your gonna make yourself sick and it wont even be caused by the drug! Eat something solid and drink milk 15 min before you take it. It will totally coat your stomach and you won't get sick. If you let the tooth infection get worse you will probably get sick to your stomach from that. And if you keep putting off taking it, you will be sick from worrying! If your mouth is too sore to eat solid food, eat mashed potatoes or very mushy egg salad, it has the same exact effect! TAKE THEM!