Endometrial biopsy advice please

Ivee
In short- I had a failed <a href="https://glowing.com/glow-fertility-program">ivf</a> cycle this month.  My dr started me on stims wednesday for another cycle.  Dr also scheduled me for an endometrial biopsy for monday.  Can anyone tell me about that.  Is it painful?!!  Nurse called me to tell me to take tylenol an hour before i go in for the appointment.  
Thank you.