You are 17. You have not mentioned since when the swelling is there and increasing / reducing. Is there any trauma.
It could be hernia / lymph nodes / varicocele / spermatocele.
Chance of it being artery swelling is very less.
Next Steps
Meet a general surgeon today.
Health Tips
Dont keep pressing it. Dont try to push it. DONT APPLY ANY HOT PACK OR ICE OR OINTMENT.