I've been on amoxicillin for tooth extraction, and today i just let out a loose, yellow colored stool. is this normal?

Yes it can be: Antibiotics such as Amoxicillin kill bacteria. Bacteria reside in your gut and if a certain population is killed by a particular antibiotic then the function of the gut will change, i.e. What it absorbs and excretes. If the stool color change is related the the antibiotic action then try eating yogurt to repopulate the intestine with "good" bacteria. You could also consider changing antibiotics.

Yup: All broad spectrum antibiotics disrupt he natural bacterial flora of the gut. Take probiotics for the duration and for 1 month after antibiotic use.

Gastric microflora: If you have been on the antibiotics long enough it could have killed off many of your healthy gut bacteria which may have lead to the stool issue. Try some probiotic infused yogurt such as activa or greek yogurt to replenish some of these healthy gut germs. Eating 2 or 3 of these a day for the next few weeks should help. If not then see your doctor.