What to say to someone who isn’t getting pregnant

Hi guys. My friend, who’s quite a bit older than me, is trying for a baby and is struggling. She lost 2 babies earlier this year and we just took another pregnancy test together and it’s negative. She seems really heartbroken (as anyone would be) but I’m just not sure what to say. I’m 19 and not really experienced this. As someone who has lost a baby, or is struggling to conceive, what would you like to hear as words or actions or comfort??