period early... need advice!

On Monday I started bleeding. It was extremely light and only there a few times before it stopped at night time. Then Tuesday I had the same. Weds it was there again in the morning, and got a little heavier in the afternoon; nothing at night. Now it's back again and heavier still. Here's what I don't get:

- I've had no cramps.

- it's a week early.

- it's still only there when I wipe really.

- it's lasted for more than 3 days, which suggests it's a period but it's nothing like a normal period.

-bright red, no clotting.

- I feel run down and tired; and my boobs feel massive.

No idea what's going on :-(. anyone have any clues??