Something doesnt seem right.

29th Dec 2012: Expected to have my period already. Last period begun 29th Nov 2012.

30th & 31st Dec 2012: Home pregnancy test is negative.

31st Dec 2012: Had PROTECTED sex, very careful that the condom did not break, or slip.. and even though there was probably no need to, spent $50 purchasing Plan B One-step pill (which i could only manage to buy 48 hours after the time of intercourse, but it mentions it works within 72 hours)

2nd Jan 2013: Taken the Plan B One-step pill

3rd Jan 2013: Get spotting / pink, light red period beginning (usually its pretty red & heavy)

After reading stories from possibility of getting pregnant even WITH a condom, even after TAKING the morning after pill, and now after light period.. I really have no clue who or what to trust anymore.

For God's sake, what should I do to determine I'm NOT pregnant??