Out of shape?? Currently 22 weeks and 6 days

Heather
I am still very active during me pregnancy thus far, well as active as I can be. And today I decided I would try to go to the gym with my husband and I could only stretch and walk briskly on the treadmill for about 20 mins then I started to get weak and on of breath with some cramps. I had to sto does this mean I'm out of shape now that I'm pregnant!!