1 poitive test followed by 2 negative tests

Yesterday was the day that i should've started my period although they are not always accurate. In the morning until about 1 in the afternoon i was experiencing very little brown spotting then nothing. Took a pregnancy test on my lunch break at about 1 and it showed a very faint line so here i was thinking i was pregnant. Decided to take the next one this morning with my first mornings urine and it was negative. Took another at lunch today except this one was first response because once again, i was spotting all morning and then it stopped. THis one was negative as well. When i got back from lunch I went to the bathroom and of course iw as all of a sudden bleeding more heavily than this morning. THe color wasn't very red it was more pink than anything, but i think i'm starting my period. Is it possible that i had a chemical pregnancy? Should I wait and take a test next week? Please advise! %-)