Low E2 & SHBG? Help interpreting blood work?

Beth
Hi ladies,
​I received the following day 3 blood results:
FSH: 5.5 mlU/mL
​Prolactin:  10.92 NG/mL
​Estradiol, serum: 0.21 pg/mL
​Free estradiol: 10 pg/mL
​SHBG: 34 nmol/L
​Looks like estradiol and SHBG are super low?!? What could this mean? I can't find much information on low levels, only high.
​My 7dpo progesterone was also a bit low (9.86 NG/mL).
We've been TTC for 2+ years. Also, I have consistent luteal phase spotting (3-5 days) every month. Any thoughts on interp. or resources to read would be a big help.
 
​Thanks!!