Is first few weeka supossed to be this stressful?

Ok so on the 13th i got a BFP going by LMP I'm 7 weeks 3 days.

Last Wednesday I went for a dating ultrasound which would make me 6 weeks 4 days based on LMP they could see large follicles, thickening walls and no sac. Was told could be too early.

Today I had an appointment with my maternity dr she thinks I'm roughly 5 weeks.

I have a ultrasound on the 27th because by LMP I should be 8 weeks 2 days but if my dr is right I be about 6 weeks. Now I'm nervous for this appointment because what if they still can't see a sac?

I've had symptoms for weeks and in the last week I've gained 4lbs.