I've been having pain in the center of my belly near bellybutton. a fullness in the belly, when i push on it or lean forward the pain worsens. pain goes up under ribs.

Belly button pain: May be gastritis/constipation or a hernia( umbilical,spigelian). Since it is painful seek medical attention today, may need anti-gastritis meds like prevecid or milk of magnesia (magnesium hydroxide) for constipation or surgery referral for hernia.

Need an exam: Your type of symptoms can't be guessed at via HT. You need to see a physician for an exam if your problem continues. Sorry we couldn't help.