Sept Egg Retrieval

Hello ladies! After 2 years TTC and undergoing many surgeries and procedures to try & help conceive with PCOS...DH & I are going through our first IVF treatment. After 3 failed IUI's with Clomid, we are currently on day 8 of Menopur, Gonal-F and Ganirelix. Based on ultrasounds and blood work it looks like egg retrieval is set for next Weds or Thurs. Does any fellow IVF buddies have tips or advice on how painful it was after surgery? I've been told to drink plenty of water and Gatorade and wear cozy socks. Scared, but excited at the same time.  I wasn't sure if a heating pad was safe during or after treatment. Thank you!