Hi, my LMP is 18/7/19. Did iui on 31/7/19. Checked for pregnancy on 19/8/19. Positive. My beta hcg is 942.57. on 20/8/19 we went for transvaginal scan to see gestational sac we cannot view at this time. Doctor told me to come 3 days later. And I have mild cramp on my left side I m really worried is this could be ectopic pregnancy? And how to calculate my pregnancy week? Is this too early to see sac? Please help me.