Was that your only miscarriage. Because if you had more than one then you are considered high risk a d you should be seeing your doctor more. There are also test that can be ran. You can suggest a chromosomal analysis, make sure your hormone levels are fine, not be on your feet as much as the baby develop, but make sure you advocate these things because these doctors won't take the necessary steps. But good luck and I hope all goes well.
I'm sorry for your loss but congrats on the new pregnancy. Try not to worry, there is no reason why this pregnancy won't be successful. What you could do is explain your worries and history to your doctor and ask for an early scan at around 7-8 wks to help ease your mind. You may also be able to have more regular scans depending on your doctor.