Is there still hope?

My last period was Feb.4 and I believe I ovulated around the 15,  but I noticed spotting on the 22, only with wiping.  I am expecting my period on about the 4th, but last night, and this morning I noticed light spotting again, I thought that it may be heavy this morning as usually when I start it is very heavy, but now I don't notice anything.  The blood is dark brown, more what I would see on the last day of my period.  Could this be pregnancy spotting? I took a home preg test 3 days ago and it came up neg.  Could the first spotting have been the sperm reaching the egg?  Do I have any hope?  Thank you for any responses, I appreciate it.

[kindergal]

You never know.....until af shows her ugly head, there is always hope.  Take another test tomorrow AM since that is when af is due.