I think i have penis inside my vigina how possible is that

is this a joke?

I had the same confusion when I was little and I saw the "lips" of my vagina protruding once while I was peeing. If it's something visual that makes you think this it may just be the lips placed oddly or in an uncomfortable position. If it's something else that makes you think this (especially a physical feeling of having something inside) I would see a doctor. If you're in pain see a doctor. If it's just a mental thing I'd say this: If you've ever been to a gyno they would have told you if your vagina was abnormal. If you haven't maybe go see one. You don't even need to say anything. Just go for a routine check up and they'll tell you if something is abnormal. I would guess you're just confused and your vagina is completely normal, but if you're in pain I'd check. 

Over the years, I have felt a penis like erection, protruding towards the vagina opening. ( Not my penis) inside many different womens vaginas. The head is shaped like a penis, with an opening. I think it's a very aroused cervix. After a few seconds of touching, it always retreats.
You are correct, I believe all women have this.

When I was having sex once with my wife I penetrated her so deep I think I hit her cervix because it felt kinda pointy.