I am 17 years old... i had unprotected sex on dec 19 2006(with no protection what so ever), dec 14 unprotected sex but two days later i had taken the contraceptive pill... dec 21-24 i had an irregular light period(mine are usually the third of themonth and last 5-6 days with heavy blood flow the first three days)... i have been urinating frequently, started spotting brownish sometimes pinkish red, my lower abdomin has been tender sometimes pain and slight bloat; and sort of an itch once in a while, fatigued, and eating a lot more than usual... im really confused and worried about whats going on... i had a positive home pregnancy test on january 17th in the morning, january 18th had a negative test at planned parenthood. help!!!!!!! should i be worried?

thank you,
christina