Need help! pseudo sac?

Hi ladies!

So I had an ultrasound today, I'm meant to be 6+2 but the ultrasound tech said I was measuring at 5 weeks as there was no yolk, only a sac. She had a good look round my ovaries etc and couldn't find anything else. However they have told me that it may be a pseudo sac and therefore they have sent me for bloods to be taken and again in 2 days time to check my hcg levels are doubling as they should be. I'm now really worried! They have booked me in for another scan in two weeks time but until then I'm just going to be panicking :(

I've had no bleeding, shoulder pain or diarrhoea so I'm hoping everything is fine!

Just wondering if anyone has been through anything like this and what happened?

TIA xx