AIO found pregnancy tests in our bathroom cabinet

I (24m) live with my girlfriend (24f) and I just today found a pack of two pregnancy tests (with one missing) under our sink in our bathroom. They were tucked way in the back behind a makeup bag of hers which seems intentional like she was hiding them. I don’t want to overreact but I can’t help feeling this is tied to cheating for two reasons:

  1. Why would she not tell me about a potential pregnancy scare unless there were bad reasons for said scare.
  2. We always use protection and she’s been late for her period before so why a pregnancy test now after three years of doing it with condoms.

Is she cheating on me?

Again I don’t want to overreact and accuse her of anything, so I won’t. But I do need to ask her about why she wouldn’t tell me about her test, and also why they were seemingly hidden.

Thanks for any advice

Edit: initial response is overwhelmingly that I’m OR. You all are right, I posted this immediately after and without enough thought. No reason to believe she was cheating earlier, besides infidelity in her distant past relationships. Thank you for grounding me here