Help!!

Marisela
I'm 4 weeks 4days that's what <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> says but doc say I'm 6 weeks. I'm confused yesterday I went to ER since I was spotting very light but still went  I had an ultrasound done vaginal the only thing they saw was gestational sac no yolk sac or fetal pole! Could it be ectopic pregnancy? My hcg level are in 6000.