Trying to get pregnant

So my boyfriend and I have been in a committed relationship for 3 years now and decided we wanted to take it to the next level. We have been trying to have a baby for months now and even tracked my ovulation and really tried to get pregnant. However my boyfriend just confessed to me that he was heavily abusing drugs years ago and wondered if this could effect us getting pregnant. Any comments or feedback would be appreciated as he’s to shy to get tested to find out his sperm count but we really do want this child