yeah wait till you know for sure your pregnant, then tell the father and your grandparents that way you know you are definately pregnant.
its great you have a friend who wants to support you with this, friends like that are hard to come by. but its great he wants to help and be there for you.
i know your stressed, i have been there, and i know its hard to tell your loved ones something like this, but when you find out if your pregnant, the earlier you tell them the better. and people will come around, my mom was really angry with me at first, but now that my son is born and hes noticing people and all she loves him to pieces, she loves being a grandma and loves her grandson. people will come around, it just takes a little time.
its great your going to see your counsellor too.
all the best hun, and you need to talk you can PM me anytime.