Your husband's semen shows presence of pus cells but adequate sperm count. WHO criteria lays down a count of 20 million good sperms as sufficient to have normal pregnancy. A couple is infertile only if pregnancy doesn't occur after two years of unprotected consummation of marriage. E. coli is the commonest organism for urinary infection and not to get scared of. The commonest cause of E. coli infection in young females is sexual activity and I am not surprised that you stopped having infections while you abstained. Commonest cause of pus cells in semen is chronic prostatitis or seminal vesiculitis, a common affliction seen in upto 20% of young population without much ill effects. You should also not expect any changes in semen till at least 3 months after starting any treatment, as sperm cycle is approx 100 days, meaning sperm produced today will be visible in the semen only after approx 3 months. You both should approach a fertility expert for proper advice. All problems you have stated regarding your husband may, in fact, not be related to your inability to conceive.