First, I'm sorry for your losses. I know how devastating a miscarriage is. Unless your OB is a specialist in recurrent pregnancy loss, I'd consult with an RE (reproductive endocrinologist)who is. They can have a series of tests done (pregnancy loss panel) and test for other things prior to you getting pregnant again. For example, we found out that I had immune issues that needed to be treated in order for me to continue a pregnancy. I did infusions prior to getting pregnant (via IVF) and a week after getting a positive beta. I was also on Heparin for one cycle and then Lovenox for the last three cycles for clotting issues. Do have your progesteron levels checked. My last miscarriae was due to low progresterone, but the clinic coordinator (wha has since been fired, but too late for me) only did a repeat beta when I went in with spotting and bleeding. I didn't know to ask to have the progesterone checked as well. I took baby aspirin for my current pregnancy until it caused a scary bleeding episode at 9 weeks, so discontinued it. While an OB may mean well, (I love mine, but I still went to an RE - several to be exact, in order to finally have children) they are not always the best medical practitioner to see for your situation. It took us 17 years, a lot of pain, and a lot of money. I hope your journey to parenthood isn't nearly as long. Good luck to you.
...and you didn't say how old you are. If you're 35 or older, don't waste time at the OB. I know far too many women who regret the time wasted with an OB, when they really needed to be aggressive in trying to conceive. By the time they got to an RE and found out what their issues were, precious time had passed and made their journey even harder due to their age.
And while trying to reduce stress is great for you emotionally, there are studies that say it has no bearing on the odds of you getting pregnant or not. Sorry, but as someone who has battled infertility for far too many years, the last thing we need is someone to place blame on us for a physical problem. All the stress reduction in the world won't help with immune issues, clotting disorders, or other medical problems. Again, good luck to you.