What does lower back pain mostly on the left slight cramping i have irregular periods and nausea mean?

well if you are sexually active it could mean you are very possibly pregnant, have you missed your period, when did you start getting these symptoms and how far along would you be nausea comes around th 6 to 8 week of pregnancy those sound like fairly common prego symptoms take a test but there are several other reason for those symptoms too so to be sure take a test but read the instructions and use morning urin, before you drink anything, remember stress cAN CAUSE a HUGE role in how you are feeling