Don\'t know much about pregnancy.

Okay, so i had unsafe sex five days before my period was supposed to start.
i am on birth control, but i havent exactly been on time, and remembering to take it everyday, and i missed a pill two days before i had sex.

I took a pregnancy test, nine days being late. it was negative.
But that night i started what i believed to be my period.
I cramp, but i get pink or brown discharge, and it isnt enough to cause me to have to wear a tampon or anything. and it spotted or what not, and was done, then happened, and now it has ceased completly.

I am very regular with my periods, and start like clockwork.

I have looked online, and do not know if this spotting is implantation bleeding or what. My periods are never like this, ever. Im not having morning sickness, like vomiting. but i have food cravings, im moody, more then i ever am, irratable, my appetite has increased, im really tired, headaches but they are light, my lower back hurts every now and then. I am nausiated after i eat certain foods. like i had a milkshake the other day and ugh..didnt sit well. or spicy foods.

I am confused, and i dont think i am thinking clearly due to my fear and confusion. plus i dont know much about pregnancy.


help?