What makes you think that you are infertile? Have you had a sperm count done while off all the gear for at least 30 days? Also it is possible to produce adequate sperm counts, but the sperm are deformed or not healhty enough to make the journey to meet the female's egg.
According to the Doctors at the Harvard Reproductive endocrinology Dept, you can not accurately test for adequate sperm production and adequate HPTA function until off of hormones, steroids, and clomid ect for at least thirty days.
This link will take you to a very good illustration of the Male HPTA and reproductive endocrinlology. As they say a picture is worth a thousand words.
http://www.elitefitness.com/forum/attachment.php?attachmentid=35002
Most people are amazed to learn that neither estrogen or testosterone play a part in the negative feed back loop for FSH production. Or in simpler terms, the level and presence of inhibin in the blood is the on or off switch for FSH production and not estrogen or testosterone.
Now for some clarification. HMG or human menopausal gonadotropin is actually composed of FSH and LH, and it is distiled from the urine of post menopausal women. You typically find this medication in 75 iu vials along with a vial of the appropriate type and amount of solvent.
On the other hand, most HCG, human chrioinic gondadotrophin is distiled from the urine of pregnant women. You can get rHCG or recombinant (man made HCG), but it is considerably more expensive. Most home pregnancy tests are looking for the presence of HCG.
HCG is an analog for LH which simply means that it can lock in on the LH recpetors in the leydig cells of the male testicles and trigger the development of testosterone (Just like LH does) assuming the man does not have primary hypogonadism or testicle failure. Also it is possible to shut down your natural T production through the use of too much HCG.
All increasing T production through the use of HCG is going to do is to drive the testicles to produce sufficent T in them to create a sperm friendly environment. HCG and LH do NOT produce sperm. It takes FSH to stimulate the sertoli cells to start the production of sperm. If for what ever reason, your hypothalamus will not produce GnRH, fertility drugs are likely your only hope of becoming fertile.
Here is an excerpt from the medical docuements for this drug:
REPRONEX (HMG )is also indicated for concomitant use with hCG for the stimulation of spermatogenesis in men who have primary or secondary hypogonadotropic hypogonadism.
If more FSH is needed, doctors will use rFSH in the form of folistim or any number of branded gonadotrophin preparations that contain FSH. These drugs are more commonly used for female fertility, but they will work for men once again asssuming that you do not have testicle failure.
I can all but guarantee you that your doctor will NOT start any fertility lab works ups until you have been of the gear, HCG, and clomid for at least 30 days.
As a side note, long term use of weed is famous for increasing a mans estrogen levels and possibly causing gyncomastia, and male infertility can be caused by something so simple as pants that are too tight or some clothing arrangment that keeps your jewels too hot for sperm production. This is why they hang low when they are loaded and ready. If they were too hot, the sperm will die. If the jewels are too cold, well you know they pull up close to the body in an attempt to get back to the ideal temp.
Best of luck.
PS "Provironum" or most likely Proviron does not bring about fertility. Proviron is a form of synthetic DHT, and as we all know DHT is a far more potent androgen that just plain Testosterone. While DHT will not convert to estrogen via aromatase enzyme activity, DHT is not very anabolic.