5 days late, 5 days bleeding, now brown discharge and pinkis

I don't understand. I had sex with my boyfriend then i was late for my period with all the signs of pregnancy. I took 2 pregnancy tests, both negative. After my 5th day of being late on my period, i had brown discharge, then bleeding for a few days and now it's back to brown and pink-ish discharge. I really don't know what to think.
Please help.
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