implantation bleeding experiences?

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Hi all, any thoughts? 
I started getting pink/brown spotting about four days ago (it started with a pinkish jelly) Over a week earlier than my actual period was supposed to start. Today I've barely gotten anything. I had some very mild cramps as well over those few days. I took a pregnancy test and it came back negative last night. Do you think it's still possible I'm pregnant? I'm asking because the internet says implantation bleeding is typically two days- but what are your experiences? 
Thanks in advance!