Can't stop thinking that I'll miscarriage again.

I had two miscarriages just over a year ago and have just found out I'm 4 weeks 3 days pregnant again.

I just can't stop worrying that it will happen again. Especially seeming I'm have a bit of brown discharge like my other two pregnancies (a bit less this time tho). My doctor doesn't seem overly concerned about it but it doesn't stop me stressing because it's the same thing they told me the other two times.

Can anyone give me some advice on how to stop stressing over it or had a GREAT outcome after having the two miscarriages?