Thanks for you quick response.
So I took aciclovir 400mg BD for 12 days prior to the first test which I took 13 weeks after the last time I had unprotected sex.
The second test I took I’d been on 400mg BD for 32 days and that test was 16.5 weeks after my last unprotected sex.
I’ve now been off it for 8 days, and plan to stay off it. I have another test paid for but I don’t want to take it if it will be inaccurate as I have to pay for it privately.