My period is 14 days late, urine and blood test~ negative. lower back pain, swollen breasts....i feel pregnant. is it possible for me to pregnant?

Unsure: Pregnancy tests should be able to detect HCG at 4 weeks gestational age.Reasons for missed /late periods: low body weight, obesity, marked weight gain or loss, over-exercise such as in endurance athletes, breast-feeding, stress, illness, eating disorders (bulimia or anorexia), travel, hormone irregularities, drug use, medications (i.e., birth control) or med problem (polycystic ovary syndrome or