Is this actually happening?

Okay so my cycle is always right, 30 days. My period is 1 week long and so is my PMS. It was estimated on this period tracking app I have called Clue that my period was supposed to start the 26th. Because it started the 28th of last month and carried to this month even though I had my period that month. I had sex on the 24th of this month and it was unprotected. I've been putting all this stuff off because I think it's just hormones. I think I should wait at least 3 weeks to know for sure. What do you think?

Update: Turns out you can get pregnant even on PMS