Don't know what to think!

I started spotting brown/pink on Saturday at 11dpo. Continued sparadocilaly all through Sunday. Yesterday, I wiped first thing in the morning and had a lot of bright/dark pink blood and figured AF was starting.  That was it, just that blood.  I had a tinge of pink cm last night.  This morning I'm 13dpo and there is nothing.  I might see a hint of brown but it's mostly just clear sticky cm.  I've been nauseas on and off.  I tested this morning and bfn.  Does anybody have experience with spotting and bleeding and then get a bfp?  Last month I spotted for six days prior to AF, but it never went away like this.  It just led right into AF.  Also I've been cramping on and off.  Thanks for listening, I would love to hear others experiences!