am I pregnant?

From the 2nd to the 8th I've had light brown discharge. I have had nausea for 3 days now. And my nipples have been sore for 2-3 days now also. I've had a miscarriage in September. My cycles have been so crazy so idk when to test. If I am I'm 3 weeks exactly. I had a test on the 8th and it was negative. I think I did it too early. I never have nausea or sore nipples. I just don't know when to test.