Yes, it’s normal -- annoying but normal. When you are on your period, your hormone levels are low and it takes estrogen to make a moist vagina. Within a couple of days of starting your period, your estrogen has kicked in enough to moisten the vagina, but until then the vaginal wall is pretty dry. If your period flow is light at first, it won’t be enough to prevent your vagina from feeling dry when you put in a tampon. You can try using a little water-soluble lubricant to moisten the applicator and make it more comfortable to slide it in.
Even though you’re on your period, your vagina could feel dry when it’s time to insert a tampon. If you don’t have time to wait, try using a pad for a short time and then try a tampon again a little while later. If you only have a tampon, try to relax and take your time. Vaginas are not a so eventually you should be able to insert a tampon as usual.
This is normal, and at the same time, ridiculously inconvenient and uncomfortable. It really peeves me when I try to put a tampon in, but can’t. Doesn’t it seem ridiculous to be on your period and yet unable to put a tampon in? Usually when this happens to me, I just bite the bullet and use a pad that day. I’m really not a pad fan, but I’d rather wear a pad than have to deal with a tampon when my vagina’s dry. Not only is it uncomfortable to put a tampon in, but sometimes it’s still a bit uncomfortable once it’s in. I find that switching to a pad that day is the easiest and quickest solution.