Working out

Any other moms out there that workout a lot? Before getting prego I was working out 45-60 minutes a day doing weight lifting and cardio. Now being pregnant (I’m only 6 weeks almost 7 weeks) I can barely make it 30 minutes. Is this normal? I am just getting to down on myself and worried about weight gain. I know this sounds stupid, but with my first I was not fit at all and not working out or eating healthy. So now feeling like I’m headed back to that it freaks me out. Any advice?