Need Help Announcing to My Parents

I found out I was pregnant a few weeks ago, and don’t have my first appointment until April 10th, but I was wondering if anyone had any advice/ideas on how to give my parents this onesie & completely surprise them?? It will be their first grandchild, and my mom has been eyeing me since me and my husband got married for children so I know they’ll be happy; I just want to completely surprise them with it and do not know how to go about it. I thought about putting it in a box and leaving it on their front porch, but my mom may think that’s strange and not open it lol. Soooo any one have any ideas/sneaky plans to help me go about this? I’m not telling them until next week after the first appointment, so I have time to hear every idea!

(btw I bought this on Etsy from Bambino World Boutique) 😊