Help 🤔

I’ve only ever had sex once. I had sex on the 5th of August, and I logged in the app I had a period after that from the 6th Of September to the 10th - so I know I’m not pregnant.

However, I am 12 days late on my period this month and I know there are a lot of other reasons that I could be late besides being pregnant. So I’m just wondering what them reasons could be, and if I should think about getting checked. Just to make sure. Thankyou.