Pressure from finger used for examination (no matter how hard it may be)doesn't damage the bone or bone graft. Your body did not take up the bone graft and the area is occupied by granulation tissue ( inflammatory tissue)and so even a little pressure might have triggered the pain. Get the latest xray of the site and see if everything is okay.if it is found that the graft site is filled with granulation tissue, go for immediate removal of implant and wait for 45days and then get a new implant done in that site.
Sounds like only a complete evaluation including x-rays can determine what may be going on. Possible failure of the implant to osseointegrate. Its hard to speculate in this forum without more information. See your dentist who placed the implant as soon as you can.