What's In My Vagina???

Okay call me slow, call me uneducated but thats what I'm asking. So my boyfriend loves to finger me... so get me ready you know for the real thing (wink). Well he likes to do this trick to me it feels like he's twirling it around something in my vagina. (And it feels 😩💦💦💦💦) He won't tell me what he does with his fingers 🙄 ( like really mf my fingers are too tiny to try to be reaching up there) But anyways. Tonight we had long sex (nothing rough, just slow strokes Bc he's 17 and I'm 18 and he lives with his mom still lol) and afterwards we took a break and he starts fingering me again. He told me something felt different like he Pushed something up a little bit. (Not like a tampon or any object like obviously its something apart of the vagina) but I just wanna know what it is... can it be moved... is it a bad idea to mess with it, is it completely safe?