Legal Question in Family Law in Pennsylvania

No. But does he want to see you? Him being an adult means he can associate with whomever he wants and that includes both the freedom to see you and the freedom not to see you. I wouldn't just show up unexpectedly on the doorstep, but then I don't know all the circumstances. If there is a relationship already there, then it might be ok. But it might be a shock if your son was adopted as a baby and doesn't know anything about you.