Nausea, bloating AFTER period?

I had a late period that lasted about 2 1/2 days, with about 2 days of normal (but light for me) bleeding, followed by about 3-4 days of very light and erratic spotting. 
This is now about a week later, and I've been suffering for nearly constant nausea for three days now and I'm very bloated, with occasional light cramping. I've taken 2 cheap dollar-store pink dye tests and they've been stark white negative. Anyone ever have a similar experience or ideas on the situation?