help! what to do?

when i gave birth at this hospital, the father of my child gave my son his name and signed the affidavit of paternity since we're not married... he left us at the hospital and never came back... pnahold ko registration ng birth certificate ng anak ko... tagal nya di ngpakita so i changed my son's name into a totally different name without telling him... few weeks later ngpkita sha... ever since then every now and then ngpaparamdam sha... he rarely gives support to our child, rarely visit the child, never a father to our child though pag magkasama cla i can feel that he loves his son.... ok communication namin d lng sha ngpapakita at bihira mgbigay ng support...... now here is my concern... i have a feeling na may iba na sha, may nabasa akong text indicating n may iba n sha... so i told him about the name change... nagalit sha... can he file anything against me for changing my child's name without his consent? he hasnt been much of a father anyway...