Delayed Period

Hello Ladies!

I hope someone can give me advise.. 🙏🏻

I am married with active sex life (but no kids yet) 🥰

I had my last period last July 21 and i was expecting to have my next period atleast last August 18 (since I am regular).

The thing is, until now my period haven’t arrive yet (today is August 25).. am almost a week delayed. Addition to that, i feel something different on my body, like I have a symptoms of pregnancy 😊 so to confirm it, I tried 2 kind of pregnancy test this morning but both results were negative..

Are there any reasons about this? Thank you in advance to those who will make time to comment 🙏🏻