Is it safe to take amoxicillin with macrobid one is for a tooth i just got a root canal in and the other is for a uti?

Yes, but....: it would be better to just be on one. If you have already been on the macrobid for 3 days, it is fine to stop it and just take the amox. In fact, there is a good chance that your UTI is sensitive to amoxicillin and you don't need the macrobid, too. To be safe, you can call your doctor's office to see if they did a culture on your urine and find out what it's sensitive to. Take probiotics, too!

Yes: There is no interaction between the 2 medications so it should be no problem. Amoxicillin could also potentially cure the UTI if the bacteria causing it was sensitive, but I wouldn't stop the Macrobid.

Yes, it is safe: Amoxicillin is broad spectrum, hence it can be used to treat both conditions.