Faint cramping

Devon
I've been having this constant faint cramping on my lower right side as well and my lower back on the same side.  I am now 7 days late and have taken one pregnancy test which as come back negative.... I dunno if this is an early sign of pregancy or not... I have also been extremely tired for the past 5 days and by extremely tired I mean in a 24 hour day im asleep more then im awake. If I am pregnant is the faint cramping in one area normal? Or could it be a sign of complications?! Also when should I test again?