I got my period on Feb 9th. Then on Feb 22nd I spotted brown but lightly through out the day. I had unprotected sex on Feb 23rd. Now I'm 5 days late for my period on my regular 28 day cycle. I took an at home pregnancy test after being only 3 days late but it came out negative. What does this mean?

It may be that your cycle is off this month or you could be pregnant and the test didn't pick it up yet. Wait several more days and see if your period shows up late. If still no period, try another pregnancy test. If that one is also negative, either wait until next month and see if you miss that period as well, or you could see your doctor before that time.