So excited but can't stop worrying!

I finally got my BFP! Over a year and half ago I got one and at 5 weeks I had a miscarriage. I was devastated but still hopeful pregnancy was possible and for 18 months I got negative test after negative test and I was begining to think it would never happen. Now I'm 6 weeks! So excited but I can't stop worrying that any day I'm going to lose it. When will this worry go away so I can just be happy?