Can a man who willingly did not wear a condom and willingly ejaculated inside a female take her to court on the allegations that she set him up because she turned up pregnant after saying she was on birth control
Birth control is not 100% sure fire safe. The fact that you did not prevent a possible pregnancy is on you. My suggestion is have a DNA to see if this is your child. File a Petition for Paternity - settle the matter amicably.
Do a DNA test to determine if he is the father.