Don't know

So I've been having light cramps on and off and bad lower back pains , my breast are tender but not badly..I had my period last month and to my shock it only last 3 days that have never happened before...I took a pregnancy test last week and by accident in the container that I put the test in had too much pee so some went into the test itself and in the result window but before discarding it there was a bright line and a dull line..I'm planning on taking a another one in a couple of weeks but i don't know what to think...any thoughts