Hi i am now 18 days late today went to the doc 4 days and neg urine test, she said to come back next week if period still not here, i just had very very light brown thing when i wiped myself after going to the toilet just now. What does that mean,i just want to know as i smoke and would hate myself if i am indeed pregnant. I have never been late only by a day or 2,any suggestions?thanks in adavance