In rare cases, yes, it is possible that the pain may be worse.
Worsening of symptoms has been reported by only 2 women to date (risk <1%) both of whom had multiple surgeries in the area of the perineum (pelvic floor). It is thought that abnormal muscle/nerve connections may be responsible for this.
This is a very rare event and careful consideration should be given if you have had more than one surgical procedure to the area to be injected.