Help please! :(

 My fertile week according to the app was from July 24-July 30 and I feel like it's accurate since I had CM ... I have long cycles due to Irregular periods. My next period should be coming up next week I believe,. I've been taking pills to help me regulate my period. That was and has been the only time I've had sex. It was our first time. Should I be worried??? Could I be pregnant ??  I'm scared because I feel weird right now. A little dizzy but that could be anything,. I need help and reassurance.

Thank you