pregnant and on birth control!?!

I am freaking out! I just had a period this past weekend but realized it was only 3 days long when it is normally 5 or 6. I stopped bleeding and then today bled when I went to the bathroom! I looked up why on google and many reasons came up including pregnancy! So I took a pregnancy test at my job and at first nothing but it sat awhile and when I looked again and faint pink line was showing!! Ahhh I'm on birth control and take it every single day! How did this happen? I already have two small ones! My husband is probably going to freak! I'm going to take another test first thing in the morning just to make sure! šŸ˜³šŸ˜«šŸ˜µ