Scared of pregnancy

I had sex 2 days to my ovulation according to this app., My guy withdrawed and didn't release in me.

I have been so scared because I have been feeling sick ( fever, headache and tiredness) and I have been so scared, and my period supposed to start on 3rd June,

On 2nd of June , my period starts but it was not heavy flow as it used to be..... It lasted for 4 days but my fear is that, it is not heavy as it used to be and I didn't feel pains as I used to. (It was a light flow )

After my period ends am still feeling tired with fever.

Please I'm scared someone should help me