people say the rudest things.

L
My boyfriends ex texted me yesterday and said "the pregnancy will probably end in a miscarriage so I don't know why you're even partly excited." 
Obviously it's just her being a nasty person, but that's all I can think about now! I'm 6 weeks tomorrow, any advice on how to kick the thought? Every little cramp I get I hold my breath now. 
-side note: we are in our mid 20s does anyone ever grow up? Haha