Hi, On A 3 Month Course Of Gonapeptyl Injections, (once

Hi, on a 3 month course of gonapeptyl injections, (once monthly) for endometriosis/infertility. My third injection is in 2 days time and I have some pain and spotting.
1. Is this normal?
2. Also, after the 2nd injection I had a headache for 8 days in a row.
3. How soon after the 3rd gonapeptyl injection would IVF drugs begin? One month?
Thank you