HELP!

Okay Ladies, I'm new to this but I need opinions. So I'm currently 6 days late on my period, and I'v noticed spotting earlier today, my stomach isn't really cramping but there is pain, when I missed my period the first day, I took a test and it wasn't negative, I took another one a few days later and it was invalid. So the question is, have any one experienced this before and what was the outcome??