You’re probably fine tbh. If the diarrhea happened about 2 hours after taking your pill, it was most likely already absorbed, so it should still work.
Taking 2 pills in one day isn’t dangerous, but it can mess with your hormones a bit, which can make your period come later or be different. Also, with the progesterone-only pill it’s pretty normal for your period to be irregular or even skip sometimes.
So being 2 days late isn’t unusual. If you’ve been taking your pill on time, the chance of pregnancy is really low. If you’re still worried, you can take a test in like 3 weeks just to be sure.