2 miscarriages

I’m 29 years old I have a 5 year old daughter and I have had 2 miscarriages this year and the doctors don’t know why the pregnancies terminated themselves. They have tested every part of my body that needs to be tested and found no problems so I am able to have more kids. I want to try again but I’m so scared of another loss but I really want another baby and me and my boyfriend both are ready. I’m thinking about trying and just keeping it between us until I’m further along this time does anyone have any suggestions that can help me with a successful pregnancy this time around when it happens