progesterone question

Ok so I had a miscarriage almost two weeks ago and today was my follow up with my OBGYN. Well she said that since this was my 2nd miscarriage that she didn't want to order and bloodwork usually she doesn't take that step until someone has 3 I told her I was still worried about progesterone levels as I read on here that can sometimes be what you need in the beginning of pregnancy she told me that she didn't think that was my problem but she would go ahead and start me on it that it wouldn't hurt and once pregnant and at 10 weeks then I could stop it so I curious has anyone else done this and I'm not really sure what it help with I just know it shouldnt be low if TTC or newly pregnant I don't even know when to start using it some stuff I read said start it after ovulation