my sperm count has been killed by TRT. But like sam said you wont know unless you get it checked, which if insurance doesnt cover it, its probably a 3-$400 price tag. But like he said you can try HCG to boost your levels and a lot of guys are successful but some arent and that stuff again is pricey at about 170-$200 a month if insurance doesnt cover which many dont. But you can come off of TRT and use clomid which many insurances do cover. Clomid is usually used for a limited time and is covered quite often.
But thats risk of going on TRt is not being fertile, your best bet if you cant handle the cost of these things or they dont work is just come off of TRT while trying to get pregnant. but you wont know until you get your swimmers checked.