Tampons

Okay, so I have medical problems so I don’t get my period a lot but it’s been trying to regulate itself so this is the second month in a row I’ve had it and if it’s gonna regulate itself to every month I wanted to at least try using tampons, but when I tried it cause me too much pain to even put it half an inch in. And then even after giving up and putting on a pad my vagina still ached for around 10 minutes. Is it supposed to hurt when you first do it? Because I mean I know the tampon is bigger than the hole you’re putting it into but like wow that hurt a lot