Why it took you so long ? this is a 'DELAYED REACTION SCENARIO" However i admire you for your being open and honest...
first and foremost you ask your self now ...1).do you want to file a complaint to the suspect?
2)are are you willing to forgive him and make a compromise with him..
If your answer is no.1 - go ahead and prepare the best evidence in the court these are :DNA test / plus a witness if any.
if your answer is no.2 - it would be best to ask the help of your parents with your lawyer and sitdown with the father of your child and for me its the best option right now .
i think our brothers here is right why do you know the very well this means you have acquaintances with him in the past.
we are praying for you