Last period was 12/21 to 12/25 nauseous lower back cramps very mild lower abdomen cramps light pink/brown spotting could I be pregnant?

Period ?'s. If your period was at a normal time for you, pregnancy is unlikely, but if it were delayed, and pregnancy is possible, obtain a serum HCG test, and if positive, see your OB provider for an exam, as pregnancies can occur outside the uterus (ectopic) and need immediate attention.