Is Having Intermittent Light Bleeding After Taking Birth Control Pills Normal?

Hi, Maybe you can help me. My husband and I had a little accident on 2/13. He didn't think he ejaculated inside me, but as that was the start of my ovulation period I took Plan B, to be on the safe side. About 3 days later I had some light bleeding for about 3 days, which I know can be a side effect. The next couple of weeks I had all my pms symptoms, sore breasts, cramps, fatigue. My period was due on 3/5 but I also realized the pill can make you late. On 3/8, i started to bleed and thought that was my period starting. That evening, thinking I was in a safe period, I had unprotected sex with my husband. (stupid, I know). Then the bleeding stopped. It has come and gone lightly over the last 6 days but nothing that is like a normal period. I have taken several hpt's and all have come out negative. I know you can't give definitive answers, but is this bleeding normal? I have been under alot of stress lately and I know the hormones in the pill can mess up your cycle, and I'm just really confused. Thanks for any input.