Help me ASAP !

So I had sex December 22 a day before my ovulation that night around 2 I had unprotected sex , and I didn’t pee after I went to sleep . That afternoon I went to pee and saw brown blood in my panties so when I got in the shower I smell something fishy and it was me so I cleaned and stuff and it still smelled like it so says has pasted and it doesn’t smell like fish just smell a little musty I use summer <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> but I’ve been having stomach pain like I sleep on my stomach & I discharge a lot and I be nauseous through out the day & my period starts in 5 days and usually I feel the period coming down but this time I feel nonthing I just need somebody to help me understand before I freak out .