I got my wisdom teeth out a week ago and the bottom one opened back up today. is it still possible get a dry socket?

After a week the : Socket is likely stable enough that a "dry socket" is quite unlikely. The condition is usually found on day 3-4 after surgery and relates to lower back teeth almost exclusively. Please don't be too concerned and continue to rinse and care for the area as instructed by your surgeon. You should be fine. Good luck!

Usually not: Usually not as dry socket occurs generally a day or two after the extraction.

Little chance: You would know if you had a dry socket because you would have intense pain. Continue to follow the directions of the oral surgeon.

Probably not but...: Could be but more likely a chance for infection. Get back into office.