I'm 9 days late, and have only experienced a small amount of spotting and very very light bleeding of a light pink or brown colour. What is wrong??

Unprotected? If you have had unprotected intercourse get a pregnancy test. Your question undiciates that it is time to get to a GYN and get on BC pills and/or use condoms PLUS spermicidal foam, jelly, sponge or vaginal suppository.