So we finally got an appointment with a specialist but it isn't for five months should we start progesterone anyways?

Britney • I'm a happily married to the love of my life and I'm a 27 year old who is graduating university soon this year and is hoping to start having some beautiful babies soon! We have had one pregnancy and miscarriage at 7 weeks so far hoping for a rainbow baby
We all think I have a luteal phase defect so my doctor reffered us to a specialist but the appointment isn't until October so should we go on a over the counter progesterone cream or try to get a prescription from my normal doctor? I don't want to miss out of five months of trying for a baby what do u guys think we should do in the meantime to increase our chances?