Progesterone deficiency/test advice. Please help!

Hi! So, last cycle I used 10mg femara CD 3-7, pregnyl trigger 5000 iu, and I always take metformin 1500 for PCOS (this is second month at that dose) I had three follicle ultrasounds and by the last I had one 15mm follicle and one 20mm follicle (and tons of smaller ones). Dr had me wait two days and then trigger. We BD, but 21 day progesterone test was only 1.8. Initially, they said I didn't ovulate but then AF came 13 days post trigger and they said I must've ovulated, but there seems to be a progesterone deficiency. 
This cycle I am again taking femara and using triggering, but now I am also adding progesterone starting 2dpo for 12 days. Has anyone else experienced this? Did the progesterone help? 
Also, is there any testing I should be asking for? I'm going to ask for an US to confirm ovulation, but I haven't had an HSG and any others that might be suggested.