Advice on a serious conversation??

So I'm seeing my ex (relationship ended about 3 weeks ago) for the first time since the breakup. We're meeting because I need to tell him that I was tested a few days ago and have Trich (if you don't know what it is just look it up) and therefore he also needs to be tested. The breakup was completely his call and I still have a lot of feelings towards him and I'm just worried about seeing him for the first time post-breakup. Any words of advice on how to handle this situation or about seeing an ex again would be very helpful