Thanks so much for your reply

I was worried I was too late with the pet insurance, as I thought most of them say something like they dont pay for anything if the symptoms showed up before or within 14 days of signing up. I was about to get post office insurance as they cover pets of any age.
I think I'll sign up anyway and see how it goes. She has her follow up jabs with the vet in 3 weeks, so I'll speak to him about these tests and if there's any other options.
Thanks again
Seren