One testicle

My boyfriend has one testicle. He had the other one removed when he was 13 when he found out he had testicular cancer. We've been trying for 13 months now for a baby. I was just wondering if anyone's boyfriends/husbands has just one testicle and has it affected your chances of getting pregnant? Was their sperm count low? Did you get pregnant? And how long did it take? Thank you so much xxx