flopping a set

[Elbie]

Maybe the turn an river action wasn't clearly described. Sb is still in the hand. He started by checking the turn and then called all raises. On the river he checked, bb checked and it's on me.

Two questions:

Should I be worried about bb having 99 here and checking because of the possible gutshot of sb arriving on the river?

Should I be worried about sb having called all the raises with a gutshot and now trying to get a checkraise in.

I'm sure that bb will call with AA KK and maybe QQ so there is value in a bet.

What's my plan if I get raise by either sb or bb?