Im thinking of trying for another baby?

hi ive had 2 m/c in the last 5mths and all ready have one daughter and me and my partner are thinking of ttc again but im petrified im going to m/c again because ive already had 2. My doctor is a complete waste of time as he wont investigate why ive had a m/c twice but i feel this is the right time to have another baby but realy scared any advice welcome thanks