Is this all a big dream

I am starting to get really anxious, and doubting it all, thinking this is all to good to be true. I have wanted to have my own family for many years now, and now it has happened I am starting to worry a lot, thinking knowing my luck I will lose the baby, there won't be a heartbeat at my first scan. I don't know if it's my hormones why I'm feeling like this or If this is just me worrying. Anyone else starting to worry about it all?