A little worried

My doctor prescribed me progesterone supplements and I’ve been taking them since Wednesday evening. She said my progesterone level as of a week ago was a little low at 14 and that she would like it to be over 20. I’ve been using a tampon applicator to insert the pill and I don’t know if that is causing the bleeding or if it’s what I’m fearing and signs of an early miscarriage. It’s hard to not think those thoughts but the last time I thought I was pregnant and then I started bleeding. I’m already over a well past that point from the last time, and my first appointment isn’t until Halloween. I’m hoping it’s just from the progesterone insertion because I haven’t had any cramping and the spotting is really light. Any advice would be greatly appreciated