Need advice?

So I take birth control pills but I'm very very forgetful (bad I know). This month I had what I though was a period but only lasted two days and I didn't even need to wear feminine products. Then when my pill pack ran out and I was supposed to get my period nothing came. That was a week ago and still nothing. I took a pregnancy test on Wednesday but it came back negative. Should I take another one? Thanks for all the advice in advance!