Well ok, I will tell you what I honestly think (I think I have before, but I can't remember, lol).
UGH Vitex! I personally hate the stuff and feel like it gives empty promises, LOL. But that's me. I think you will get preggo naturally on you own, once you address the progesterone issue (which really is usually an ovulation issue, partially at least).
You can still have your appt, but just get your lab done when you need to and have them phone you your results. At your doc appt this week discuss what you will do when the results get back if they are too low or whatever, so you have a plan of attack already waiting in the wings.
And finally, sometimes when I see your charts I think that you are "That Woman" who would get preggo pretty quick on clomid ($30, no insurance, Walmart). There are tons of examples of women like that on the net or JM--sometimes a girl just needs an ovulatory boost! Or better yet, try Femara. Less side effects For Sure, and I think it is on Walmarts's discounted drug list too.
Of course, I think you most likely have everything you need to get preggo on your own naturally, and that it WILL happen (and I am not trying to sound like I am pushing drugs on you), but I would bring up the femara with your doctor at least to talk about at what point you will want to try it. It won't thin your lining like Clomid, it has no adverse effects (unless you take it when preggo), and it didn't give me ton of preggo symptoms like Clomid did. Something to think about.

I really don't mean to sound like a drug peddler, I just want all my friends to be preggo and happy!

The sooner the better! LOL