Pregnancy

So I’ve been having unprotected sex with my boyfriend (we are trying to have our own family) but my periods are irregular so it’s hard to pin point exactly when they’re due. According to the app my period should’ve started 7 days ago but so far nothing 🤷🏻‍♀️ more to the point- any advice on when would be a good time to do a test? Any tips on which tests are better quality as I’ve had a clear blue digital before and it was a false positive which was a sad moment.