Bad timing on Birth control? Long Period

I was off of my birth control for about 2 months. During that time I had unprotected sex. I went to the doctor and got my birth control and in the mean time they also tested me for pregnancy (but I'd just had unprotected sex like 3 days before so it probably wouldn't show up then). I waited for my period to start again before starting my new pill pack. I started on what I thought was my period but I was only bleeding for like 2 days and it was really light. I continued taking my pills and then got my period early this month. It has lasted almost 9 days and I am having cramping that I never had before. I've been really tired as well. Is this just because I could have started my pill pack at the wrong time or is there something else going on? Could I have been pregnant or could I be while still bleeding?