Late...worry or not

I’m 15 and I’ve not had vaginal sex but I’ve had anal with no condom. He never came so I know it’s very unlikely. I’m 4 days late according to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> and 2 according to clue. I normally have a very regular period but last month it was late aswell. There are none of the normal signs that it’s due either. Any advice? Do I worry or do I just leave it?