I also agree with AnnieBrooke, you need to get it taken care of the extra stress and infection can cause harm to baby, but it sounds like you were already getting it taken care of at least!
I completely feel your pain, I've had a toothache for a couple weeks now. My dentist thinks I have Ann impacted wisdom tooth which there's not much you can do for it while pregnant, but he gave me something to swish with that seems to be helping thankfully. I would call and make sure its ok to continue your antibiotics which I'm sure they will be ok, them take some Tylenol, and even though it is disgusting take a clove of garlic and bite down on it on your hurt tooth, and it will burn like heck for the first minute but keep it there for 5 min, it will take the pain away instantly. You can do onion if you don't have garlic, but I don't think it works as well. They both have healing and antibacterial properties as well. Clove oil is supposed to be great for tooth pain as well, but I still have to get some to try it.
Get the tooth fixed. If it is aching, it might be infected, and you do not want infection running through your body when you are pregnant.