Anyone else?

So I'm on my 4th pregnancy since having my daughter and my first symptom is usually shortness of breath.. it was starting to worry me a bit this evening so I decided to test my oxygen levels and they're not terrible they're fluctuating between 95 and 98. But when they drop I start getting panicky... my breathing is what really triggers my anxiety, if I feel like I'm not breathing good I'll go into a panic attack... just wondering if this happens to anyone else. And wondering if/when I should worry about it?