Late by 3 days!

So I’m getting a bit paranoid, my period is late by 3 days, and I did have unprotected sex with my partner. We did it when there was a 3% risk of pregnancy (according to the app) and he cum outside. So technically I know chances aren’t high, but it’s possible.

Then I also quit the pill quite recently, this is only my second cycle not being on the pill so it might not even be late and rather just less regular than I’m used to.

I did get the pms symptoms, like the sensitive nipples and bloating..... I did not get a migraine though, which I usually do.

So things are a little different and I’m just freakin out and thinking whether I’m just being paranoid or if I should be taking a pregnancy test, and if so, when should I do it, should I wait a bit longer or should I get it out of the way now?

Thanks and sorry for so much tmi and complicated question 😅