Difficultly breathing at 6 weeks..

I’m 6 weeks and 5 days and I’ve been having the hardest time catching my breath, and feeling like I can’t take a deep enough breath. I start to panic and it gets worse and my heart starts pounding and my breathing gets worse. I went the the ER and my oxygen levels are perfect and my heart rate is normal. How ever they are concerned for a blood clot in my lung, I refused the ct with contrast as the radiation and contrast doesn’t seem safe this early on and I need to really think about it.

Has anyone had this shortness of breath during early pregnancy?

Any advice?