HELP I wanna know how far along I am


I'm 18 and this is my first child and I'm super nervous. So my nurse at my gynecologist office says I am 2 weeks pregnant but this app says I am 6 weeks and 2 days according to my last period. I just want to know how far along I am because my first OB appointment isn't until May 2nd. Last Saturday my hcg levels were at 181.9 and I've been having cramps and sore breasts and extreme fatigue so I think I'm farther along than my nurse thinks.