Is my swollen lymph node because of Botox?

Unless there is localized redness and swelling around the sites where Botox was injected, it is highly unlikely to have any lymph node enlargement.  More than likely, since strep has been ruled out, this is from a viral infections which should resolve with time.  Any lump that persists does need to be evaluated by a physician. 

In your case, if the botox was the culprit, you probably would have had lymph node swelling within the first couple of days. I haven't seen this ever, but I guess it would be possible. More likely than not, you're just coming down with an upper respiratory infection. Not all upper respiratory infections are caused by strep- most are just viruses.However, if the lump persists after you're not sick any more, PLEASE be sure to get it checked out by a doctor. Good luck and get some rest!