Being terrified

I just found I was pregnant recently, and it wasn't planned at all.  It seems like the reaction should be that I'm excited but truthfully I'm more terrified than anything. People jump up and down and say they're happy for me and congratulations. Truthfully this is hard to take, and I'd rather receive something like, "it's going to be okay".  I know logically it will be, but emotionally this is really scary!