Please Please HELP

Is it at all possible to be pregnant and have a 2 day period? 
Friday night at midnight I started my period, which was upsetting bc I want to be pregnant, I bled all day Saturday and Sunday. Then on Monday which was my 3rd day I had nothing today would be my 4th day and nothing, I had a little brown discharge when I went to the bathroom this morning and that's it.
I bled like a normal period but they usually last 5 days. I took tests before my expected period and they were negative. But I've never just had a 2 day period and it completely stop like this. 
Could I be pregnant?