College Student Wants to Know if Ex-Girlfriend's Baby is His

My question involves paternity law for the State of: Colorado (El Paso County)

SHORT STORY:
My Nephew "Jack" (now 18) was dating "Jill" (now 18) who became pregnant. There was never any question as to whether the baby was his. They discussed names and Jack went to all appointments with her. He was nervous but excited about becoming a father.

Shortly before they were to find out the sex of the baby, the couple broke up for good. Jill's last contact with Jack was a phone call on 8/26 saying she was canceling the mediation session (a service through Jill's mother's insurance) scheduled for that week because she said it didn't fit into her schedule. Jill then blocked Jack's number on her phone and refused to take his calls from other phones and her mother changed her phone number. Jack has not heard a word since the call on 8/26. It now appears she canceled the session because she was in labor because Jack's mother heard from a confidential hospital source that Jill gave birth to a healthy boy on 8/27.

Jack currently has a packet of forms from the child support enforcement office, which they normally give to mothers to pursue support through the establishment of paternity. Staff in the support enforcement office were incredulous that Jack wanted to "open up a case against himself," but Jack doesn't view the baby simply as a potential payment. He's gotten depressed by the unexpected silence from the mother and thinks daily about caring for his child and all that he's missing.

We need closure. If the child is not his, he needs to be able to grieve that fact and move on, and if it is his, he wants to be a father.

MISC:
-Jill turned 18 in October.
-We don't know what Jill put on the birth certificate
-There have never been any incidences or charges of abuse of any kind
-Jack's family cannot afford a private attorney

What should Jack's next steps be?

OPTIONAL BACKGROUND:
Several weeks after the breakup, Jack and his parents showed up at the doctor for the long awaited appointment to find out the sex of the baby. Jill refused to let anyone into the exam (completely understandable), but also instructed the nurses and technician not to tell Jack and his parents the sex of the baby. Jill and her mother hid in the exam repeatedly calling the front desk. When Jack and his parents realized they were the ones calling, they apologized to the staff for the uncomfortable situation and left.

In July Jack and his family received a letter requesting their presence at mediation (a service provided by Jill's mother's insurance). Jack and his grandmother went. Jack expressed his interest in being an active father with plans to be home from college (3 hours away) every Friday through Sunday along with holidays and breaks. Jack's grandmother reiterated her offer of free day care so that Jill could attend school locally as she had planned.

Jill and her mother were displeased with Jack's plan to go to school 3 hours away (Jack has severe ADHD and attends a school with a strong accommodations program, his parents have made it clear that they will take care of his financial obligation while he's in school but he is expected to be physically and emotionally engaged with and responsible for his child and keep his grades up), but the mediator said he was encouraged by Jack's sense of present responsibility and desire to get an education to improve his ability to provide for the child in the future.

During the mediation, Jill said Jack could not be at the birth and she would not tell him when the baby was born. Jack begged Jill's mother to please at least call him right after the baby was born and she agreed, which made Jill furious. At the end of the appointment a second mediation session was scheduled, which Jill canceled (see above).