advice

So AF was suppose to start on the 8th. On the 8th I felt the cramps just like I would if it was coming and then the next day nothing, then yesterday and today i have had cramps like crazy still no AF I took a pregnancy test it can back looking negitive and I tweaked it and you can see a like. And as of right now still no AF. Should I make a doctors appointment to see if they do blood test to see if im pregnant or not ?!?