Pregnant during period ?

I’m always on my period for 5 days ...

My 2-3rd day I was light, me & a close friend had sex .. the next day it completely stopped .

It’s been 4 days, I have nausea every now & then & my breast feel a little sore on & off, I’m dizzy .. I know you can’t have symptoms right away but when I talked to a coworker she said she had hers 3 days into her pregnancy ... is it possible or am I just freaking myself out ? 🙃