What Causes Brown Vaginal Discharge After Taking Plan B?

So I began my period on April 5 and it ended on April 10. On April 11 I had sex but the condom broke but he did not come. I took Plan B 48 hours after on April 13. I was crazy worried and very emotional. I was gassy all the time, especially when I woke up. I do know that anxiety can also cause someone to be gassy. By April 17 I began having brown discharge and then it started having blood mixed in too a few days later. The blood was dark red and very liquidy and dripped out of me. By Aril 21 I had to start using a pad and the brown discharge stopped but the bleeding still continued. I occasionally have sharp abdominal pain when I sit down but it s goes away after a few minutes. I m still gassy in the morning but not as much during the day. Is it natural for the plan b side effects to last this long? AM I pregnant? Is my body reacting normally?