Bleeding after tooth extraction?

It's been about 2 hours or so, and my socket is still bleeding. Doesn't seem to have died down. I'm on my third gauze pad, and I just flipped it around to soak in more blood. I changed gauze every 30 minutes, and I've been on this third gauze for almost an hour now. Should I go out and buy more gauze? Also, I can feel the numbness wearing down, and I want to know if it's okay to take some Motrin before the pain starts to hit. Also, when should I take my antibiotics? (Amoxicillin)