Why can I feel my tampon string?

Hi,

So I have a strange situation where whenever I use a tampon, I can always feel the string right where it enters my vagina, and it's very uncomfortable, especially when I sit. I know the tampon is in right because I can't feel the actual tampon inside of me. There is no discomfort there. I put in the tampon 100% correctly, start squatting, put it in so it is slightly angled towards the small of my back, make sure to push it in until where I'm holding it with my fingers touches my vagina, push the smaller end of the applicator and remove the outer shell. Again, I don't feel the tampon inside of me at all. But, I can ALWAYS feel the string. Right at my vaginal entrance. I am a virgin, and it is about my 5th time using a tampon, and it is the same case every time. Help? I don't like pads. They're messy.