normally my periods are pretty regular, every month the cycle lasts about 30 days. My period consits of 2-3 days of heavy bleeding then 2 days of a normal light flow. This time around I had the normal 2 days of heavy bleeding, 1 day of normal light flow BUT 6 days of barely visible light brown spotting that is only visible when I wipe myself or on a tampon. I had sex on the first day before the 6 days of continuing light flow. I have also been nausous at random times of the day. Does anybody have any idea what is going on?

It sounds like your cycle is changing, ths happens to most women at least once in their lives, cycles can change in length, flow, duration etc, its just natures way of throwing a spanner in the works!