What Causes Delayed Menstruation Along With Lower Abdominal Cramping?

My daughter s first hcg is 5803; second is scheduled on Monday. Her LMP was jan. 22nd. She is upset because she has lower abdominal cramping, but no bleeding. However, she also stated she is constipated. I am in medical field, and as her mom, I am thinking could be totally normal, right? She has not been spotting; but had a miscarriage a year ago, so is very concerned. However, last year, she never made it to this point on her gestation. And this time has had no bleeding. Comments?