Pain in some not suppose to be painful areas

So I go my period like 2 years ago but I just started getting cramps. I don't really have a lot of experience with them but I was on my period and was using tampons like I always do and I started to feel like a kinda painful pressure in the v area so I took it out and just moved along cause there wasn't much blood after a couple of hours. When I layed down tho it started happening again and sometimes it goes higher or lower. I stuck a finger up there to see if I lost a tampon or something but I didn't feel anything but I could only stick the finger in like the length of the finger. Is that shallow for the v it is it normal?