10 days late?!?

I'm currently 10 days late. My period has been a saint the last three months (it's been regular since getting off the pill, thank god). At 2 days late l was very nauseous and had light cramping so I thought my period was coming but around 5 days late I had brown discharge ever since. It's started off light pink then turned brown. And now I'm at day 10 with just brown discharge and light cramps. I took a pregnancy test on day 7 and it was negative. I have no clue what's going on! 😩