Yes, it can! If you forget to take an old tampon out and it moves up into the vagina you could comfortably insert another tampon into the lower part of the vagina. If this happens, don’t panic. First, take out the tampon that you inserted. Next, insert your index (pointer) finger into the vagina to see if you can feel the other tampon or its string and try to remove. If this causes you pain or you can’t seem to locate it, make an appointment to see your health care provider ASAP. If you get to this step, don’t worry, I have removed more than a few tampons in my office – it does happen sometimes!
It can happen. I've never done it myself, but it's certainly possible. If you insert a tampon when you already have one in, just try to remove them one at a time. If, when inserting the second tampon, the string on the first got shoved inside your vagina, just wash your hands and feel inside for the string. The good news is your vagina is self-limiting, so it's not as if the tampon can get lost inside of you.
I hate to admit that I’ve been there and done that -- but I have. Once I totally forgot that I had one in and then put in another! I was pretty freaked out. Luckily, there is an end to it all of it up there. I was able to get both out without having to ask for help. But you should know that if you cannot get to them yourself you should ask for help. Never leave a tampon in for more than recommended (8 hours). The expense of your pride is cheaper than the price of your health.