Yes, there is chance it may just be a transient ulceration of your gingiva that will heal in a week and be gone. This is the logic behind waiting 1 week, which makes it a sensible recommendation at first. However, I would recommend that an x ray be taken b/c this can show if an abcess/infection has recurred in this tooth. This is standard practice to take an x ray when an ulceration appears below a tooth. It can show bone loss, yes, but it can also show abcesses and infections. After one week, if the ulcer is still present, I would recommend you see your dentist for an x ray of the tooth.
Keep in mind that sometimes the ulcer will disappear for a week or two, and then come back. This is a common occurance with infected teeth as the infection ebbs and flows. So if you see the ulcer clear up after a week, and then resume in 2 weeks, be sure to revisit your dentist for an x ray.
Reinfections do not always have symptoms associated with them. In fact, many times they don't. If the tooth is dead from the initial root canal
, then there is no nerve tissue present to fire an impulse. So do not weigh your decision based on your symptoms b/c they may/may not be present.
Finally, the fact that you just came off co-amoxiclav does not necessarily mean that you cannot have a reinfection in the tooth. Antibiotics do not cure tooth infections, they only keep them at bay. So 2 weeks after antibiotics the tooth very well may still show signs of infection.