Rectal pain?

On the first day of my period I experience sharp pains in my rectum. It's like pins and needles and makes it impossible to move or breath, from the pain. Does this happen to anyone else? I do have a spastic colon but the pain only happens on day one....also I have light spotting for about a week before the big reveal? Is this normal? Do I count the sporting as period days? So confusing being a woman