Clomid for the 35+ Crowd

Staring my first round of Clomid on CD 3 and am very nervous!  Age 37, ttc #1 for 2 years with a miscarriage at 9 weeks last July.  It appears that I ovulate each month according to OPKs. Dr. said this is just to give me a boost.  I've had my AMH tested (good), I have my thyroid checked frequently (I have thyroid disease and take 112 mcg Levothyroxine) and husband has done sperm analysis (came back good).  What am I missing?  I feel like I am not doing enough.  Obgyn said she didn't feel HSG was necessary , as I had just conceived in 2016.  I went to the only RE in the area and he was not helpful.  Very nervous about starting Clomid as I feel like it is our last option.  Hoping that something comes of it.  Any success stories or advice?