Thanks for consulting us.
I think you should have a blood pregnancy
test, a trans-vaginal ultrasound
& an Ultrasound KUB on urgent basis. As, the two most important differentials coming to my mind are ectopic pregnancy & some problem with your urinary tract
like stones. Ectopic pregnancy is a life threatening condition which must be ruled out.
Urine pregnancy tests
are very reliable but sometimes they give false results.
Wish you good health.