Using Progesterone to Support Future Pregnancies

Caitlin • I`m a married 30 y/o high school digital integration specialist. My husband and I welcomed our rainbow baby into the world 1/2017 and are excited to prepare to expand our family in the next few months.
Hi ladies, I just had a second miscarriage much to my surprise about 6 weeks after my first.  I was so surprised that I was able to get pregnant so quickly after my miscarriage and we had such high hopes since I was able to get in to my new OB's office a week after a BFP.  The Friday after I found out I had some light spotting that let up the next day but turned in to full blown bleeding that Sunday.  I called the OB office Monday morning and they got me in that afternoon to meet with a doctor.  He said it sounded like another unfortunate miscarriage so he ordered an HCG to be sure my levels went down and that he wanted me to start 400 mg progesterone, 81 mg baby aspirin, and folib to support my next pregnancy as soon as I got another BFP.  My levels went up to 44 so we thought there was still hope and that it was just some breakthrough bleeding.  The doctor started me on the prescriptions asap and sent me in for another HCG on Saturday to see where things were this past Monday.  Unfortunately Saturday's results confirmed last Sunday's miscarriage and I am devastated.
We are taking a month or two off from not using protection to let my body have a normal cycle or two. The OB (who I chose to be my OB dr. after meeting him) thinks the chemical pregnancies were either miscarried due to abnormal chromosomes or low progesterone.  He thinks 3rd time is going to be the charm with the help of the progesterone and decided he didn't want to wait for a 3rd miscarriage to start the testing that usually points to low progesterone.
My question is has anyone started progesterone as soon as they got a BFP after having one or more miscarriages?  Do they think that helped them keep their pregnancy?