No membrane used for graft on tooth #8. Is this normal practice?

For proper guided bone regeneration (GBR) a membrane is always required over particulate bone graft. The only time is can be done without membrane is when using block bone grafts or autogenous block shields. In your case, if particulate (granules of bone graft) was used, a membrane should have been used to both contain the graft and also block the in-growth of epithelium from the gum tissue, which are both critical for success of grafting.

Based on the picture you have uploaded, the area seems to be healing well.  As a routine, it is recommenced to use membranes over bone grafts after socket bone grafting.  If the area was over packed, then loss of some grafting material should not have a major consequence.  At this time you should see your doctor as soon as you can and discuss the next steps.