Am i pregnant?

cindy

Hello, i need help guys, me and my boyfriend had sex the day after my period. and on my fertile day on dec 1st. i checked the app and it says dec 4th is my ovulation day, today is 3dpo only but i feel different, i have cramps, lower back ache, always hungry,. i know its too early to feel any symptoms, but is it possible that i'm pregnant? or is it implantation already?