What could it be?

Not sure exactly what's going on..on the 29th which was 2 days late I had brown discharge then a day of red with some clear mucus just now and then next day was spotting of light pink then brown again. Suppose to start period again March 1 I've had mild nausea the veins in my chest and breasts frequent urination. I took pregnancy test couple days ago and it said negative which I'm assuming would be way to early to detect. Today I'm having more nausea feeling and discomfort in my lower abdomen would it b I'm pregnant and it's just everything getting settled or ovulation pain which I normally don't have..my mom says I'm prego lol