Can Birth Control Pills Cause Bleeding Before Periods?

Hi, i'm 19 at 5'7 1/2 and i weight about 240. I have been in a car accident. I have all my shots up to date. I don't have any allergies. I have been taking the pill, wanted to know if it was okay to bleed while taking it, like i was having my period? Before i started it i went to a health clinic to find out why i wasn't having my periods, i had gone half a year without it, So they told me to try taking birth control so i have been, but since i started taking it i been bleeding, not heavy but like a normal period, even though the lady i talked to said that i would only get it when i got to the different color pill, but i didn't. I have had it since i been taking it, I'm not sure what is wrong, i really don't have the money to get myself checked again and find out that there isn't anything wrong, since they have failed to tell me anything really. Can you help please?