If you have tried for awhile without getting pregnent (no idea how long is too long - 6 months? a year?) then go in for a semen analysis. No need to borrow trouble.
On the plus side - it sounds like you have a decent doctor who is willing to think outside of the normal box (i.e. - saliva tests). That is very rare.
that being said - you need a much stronger baseline of tests before you jump into HRT.
did you check out the blood test sticky? Ask for as much as you can get.
You need to get blood tests for the main indicators - a number of sources say that saliva tests are only really realiable for Cortisol and maybe DHEA-S. There is not much confidence in other hormone saliva tests.
Don't worry about what protocol or treatment plan you may need until you get all of your blood tests back. Most people jump into treatment way too soon. I wish I had known all of this stuff before a doc slapped a Androderm patch on me 3 years ago. It would have saved me years of fluctuations and struggles.
Given you earlier tests results, this is what I would ask for to start with (assuming you have a good insurance plan that covers blood tests):
1 Metabolic Panel (14), Comprehensive
2 CBC w/ diff/PLT
3 VAP TM Cholesterol Test
7 Magnesium, serum or Magnesium, RBC
10 C-Reactive Protein (CRP)
14 Iron and Iron Binding Capacity
15 Iron, Total
19 Hemoglobin A1c
22 Vitamin D, 25Hydroxy
23 T3, Total
24 T4, Total
25 T3, Free
26 T4, Free
27 T3, Reverse
28 Ultrasensitive TSH
29 Thyroid Peroxidase and Thyroglobulin Antibodies
37 DHEA Sulfate
47 Estradiol, sensitive
49 Total Testosterone