Some questions

My husband & I have been TTC for 22 months. We just saw our RE for the first time this past week. She was happy with both of our test results so far and sent me for some more lab work. I got my results from the progesterone test and my numbers were super low (0.015) when according to the nurse it should’ve been much higher, around (15) so she was going to talk to the doctor and get back to my next week to see what the next steps are. I have a 28-30 day cycle, I’ve never missed a period. This last cycle was the first time in 21 years of having a period that I had bleeding between periods. I guess this maybe gives us some answers as to why I haven’t conceived so far. Has anyone else has this happen? Or have suggestions on ways to increase progesterone naturally? (Besides medication—once I find out more from my doctor I will do whatever it takes to conceive and start our family)

I was a bit discouraged and frustrated about the result yesterday. Like how come my progesterone was never tested sooner? & wondering if this has been the problem from the beginning?

The doctor is also sending me for a shg—what should I expect? Is it similar to an HSG?