Period or implantation bleeding?

Elizabeth • Mommy to a beautiful baby boy
I had sex in the middle and end of my ovulation week, I've been feeling sick and I keep getting that metallic flavor in my mouth like I want to throw up, my period or so I think it was my period but only lasted two days came a day early, I've had cramps since I had sex, and I'm scared to find out if I'm pregnant because I have sex with someone while me and and my boyfriend were split up, I didn't realize it was my cycle times because I was out of state. Should I take a test so I know I'm not pregnant, or just pretend like nothings wrong, I've also been constipated and smells get to me easier than they use to.