I had an extraction\bone graft 4 days ago. Is it ok that the stitches, membrane, and large clump of bone graft came out?

It sounds like a portion of the graft may have dislodged with the stiches and membrane.  Most membranes are designed to stay in place for 4-6 weeks.  The membrane protects the bone graft and prevents the gum tissue from invading the graft.  You should follow up with your surgeon for an in person evaluation; he or she may be able to replace the graft.