I'm on my fifth month of birth control pills, but last month I took a few very late, once even missed it and took two the next day, I had my period on my off week, as usual. It ended, then four days later I has light spotting, just for a few hours, maybe half a day. It was kinda pinkish, not dark, could I have gotten pregnant, but still have a period due to the pills? I've been moody and very tired all the time, no tender breast, but they seem to be heavier, but it's only been about two weeks since the spotting. I took a pregnancy test three days after spotting, but it was negative. Is it just a side effect from the pills, or could it be a chance of pregnancy?