Dear DR. I m 27 yrs old,My cycles was irregular past 2 months taking metformin 1g at bedtime,now my cycle was normal.. this month my cycle is 6 days late.i taken urine pregnancy test today the result was -ve.i m having pain in my lower right side of my abdomin and nausea , frequent urination ..the cramps are very convincing that i should be starting my period but nothing has come down..can i take blood test??wen i should take???or i should wait for my periods??