My girlfriend and i started having sex about 2 months ago. Before dating we were friend for about a year. Everything has been going great and the sex life is great but a couple of times we ended up having sex without a condom. I am an anxious person by nature so i went and got myself tested for STIs. Before i started sleeping with her i knew i was healthy as i was tested before and had only been with her since then. After having unprotected sex with my girlfriend i got tested and all results were negative. I then approached my girlfriend and said to her that it would make me feel much better if she also got tested so we both knew we were healthy. She agreed to get tested but also got visibly upset that i asked her, saying that i do not trust her and saying stuff like "if you got tested and you are clean that means i am clean too" which is just factually incorrect and i tried to explain that to her but she didn't want to talk about it. I also tried telling her that this is not about not trusting her and just about making sure we are both safe. To that she replied she got tested in the summer. I said it would be nice if we both got an updated result. She also said "i have never been asked to do this by anyone else" which i think also made her upset.

I know i did a couple of things wrong. We should have talked about getting tested earlier, before we ever had unprotected sex, and waiting this long probably made it worse. She accusing me of not trusting her and is upset and after we talked she just said she wants to leave my house so i dropped her of at her place. I do not really know where to go from here. She said she will get tested but i also know she is upset and now thinks i do not trust her. What can i do to convince her that me asking for this test is just not a big deal and is just a routine thing?