im starting to freak out

i have a two yr old daughter. my periods have been regular for the past two yrs since ive had my daughter. my period was suppose to start on the 22 of jan. it is now jan 27 and still no period. i have been having cramps like im going to start bt still no period. i have been craving alot of cereal and been feeling really tired lately. im 5 days late and today ive noticed that when i wipe that there is a pinkish darkish color on the tissue i dont know what that is or what it means i would really like to know so if anyone can help me out that would be great!