A little penis inside my vagina?

Most likely, it’s just your cervix⁠ (cervix: The opening to the uterus, the bottom of which is at the back end of the vagina.) .

The cervix is the end of your uterus⁠ (uterus: An internal, muscular reproductive organ in the pelvis. During pregnancy, this is where a fetus will develop. The lining of a person’s uterus is also the thing that sheds every menstrual cycle in what we call a period.) , or the beginning, depending on how you look at it, and the cervix and cervical canal jut into the back of the vagina⁠ (vagina: The internal passage leading from the opening of the vulva to the cervix of the uterus.) . When you’re not highly aroused (arousal usually will pull the cervix further back), you can usually feel it by placing your finger inside, and given that it is a bit tubular, and also has a small opening on the end, it’s easy to see why you might think it resembles a penis⁠ (penis: One of the two external reproductive organs of people often assigned male at birth.) .

Next time you’re at the gynecologist⁠ (gynecologist: (Pronounced guy-na-coll-o-jist) A doctor that specializes in the health of the uterus, ovaries, vagina, and vulva. . They may also be referred to as “OB/GYNs” or, informally, “gynos”.) , you can even ask him or her to take out⁠ (out: Short for ‘out of the closet’. When someone’s LGBTQ+ identity is known to other people.) a mirror when they’re doing your speculum exam so you can get a look at it: it’s a pretty cool thing to do, and will likely clear things up for you.

For more on your sexual⁠ (sexual: About or relating in some way to sex or sexuality.) anatomy⁠ (anatomy: The body, parts of the body, or physical structure of organisms like people, animals or plants.) , have a look here: Innies and Outies: The Vagina, Clitoris, Uterus, and More.