I'm not sure Jaye, it seems unlikely as it's a commonly prescribed medication and I haven't heard any warning related to its use and TTC.

But if you're really worried, you could ask you GP for a referral for a sperm analysis (although your DP probably won't be that keen on the idea!). The results from that will be able to tell you how many sperm your partner has, and how many of them are normal/abnormal.

HTH