Please help!!!!

To make a long story short I’ve had 4 miscarriages. My doc said the next time I get preg I need to start taking progesterone as soon as I get a positive test because mine was low each time I miscarried. The problem is I’ve recently moved to a different state and since they don’t know my medical history or anything they said they won’t make an appointment until I’m around 8 weeks so it’ll show up on ultrasound. Based on my Last period and all I should be around 5 weeks. Anyways so I’m so worried my levels could be low again and waiting could be dangerous if my levels are low. So my question is, is anything with progesterone I could possibly use until I can get to the doc or could that be harmful?