Does hematospermia also causes infertility?

Depends. This depends on the cause of the hematospermia. Most of the causes are idiopathic and inconsequential. If the rest of the semen analysis is normal, then you are probably ok.
No. Hematospermia is usually a benign condition that often goes away on its own. It shouldn't cause infertility but you should get checked out by a urologist.