I'm always worrying...

Because my bf and I don't use any birth control. Weird I know but in a way, a baby would be gladly accepted anyway so it's ok. My period is due in 4 days. Yesterday on my undies I had very light brown discharge but reallyyyyy thick. I thought it was the start of period so I put my cup in. When I took it out at night there was maybeeeee 1/4 teaspoon of blood in there. Now today there's maybe 3 drops of clear and liquidy. Soooo.... What was that.