Negative test, but light period with nausea?

I started my period, at least what I thought was my period, last Wednesday. However, this time it was really light and more brown than red. Sorry TMI. But before I started my boobs were sore and I was having cold like symptoms. Well my period ended like 2 days after it started and hasn't been back since. My nausea has continued and smells are beginning to bother me. I've also got headaches and fatigue. Anyone else experience a light period when your period was due and still had a negative test, but were pregnant?