Hi,
I have had 2 previous miscarriages and have just had my 3rd this week. My family doctor says its not a problem since I have had 3 successful pregnancies. I am worried though because all the miscarriages were after my 3 children were born. I want one last child and I want to know if there is anything I could to do to prevent another miscarriage in the process? The 3 miscarraiges have all been in the last 6 months.

I'm so sorry that that's happened to you! How heartbreaking! I personally think you should trust the doctor.. if you're really worried, maybe talk to him again.
Here's a good webpage... you can check it out and decide if you want to trust her:
Can I prevent a miscarriage? (http://www.askdramy.com/preventmiscarriage.html)

In an effort to answer your question ,I researched some sites and the following had useful easy to comprehend advice.
I hope you find it useful.
I am sorry for your loss.
How to Prevent a Miscarriage ? Prevention ? What Can Help Prevent Miscarriages? (http://www.docshop.com/education/fertility/miscarriage/prevent-miscarriage/)

I am so sorry for your miscarriages.

I think this thread may help explain part of it.
https://www.askmehelpdesk.com/marriage/how-cope-married-control-freak-470375.html#post2349130

You are under a lot of stress. Does your doctor know about your husband and his issues? If not, then discuss it with your doctor. He/she may be able to give you better advice and help.