Thanks everyone for the replies!
Well, tonight was a big surprise
Due to horniness and a lack of willpower we ended up having sex, she came but I didn't for a few reasons: she had already got me off three times that morning, the condom was a bit thick so there wasn't as much feeling there, and I don't trust condoms totally, and there was other company in the house.
But it was great
That does change our plans a little bit; now we're not going to wait until November.
But the STD test is still an issue. I'm seeing her this weekend again so I'm going to follow everyones' advice and really sit her down to talk about it, and explain how important it is, especially now that we've had sex and most likely will do it again soon (hopefully not before we get tested). I'm going to sit her down and explain to her what I've written here and reassure her that I'm not just being horny, and that it's not because I distrust either of us.
I think that perhaps if things weren't so serious between us I wouldn't make such a big deal about it, but we've admitted we love each other and things look fantastic in the long term, so I think we both have a responsibility to get tested. Once we do, though, it certainly doesn't mean we have to go all out every single time we're together of course, but it's good to know in the future that if things get hot and heavy we don't have to stop ourselves because we haven't been tested.
Thanks a bunch for all the advice given here