Working out while pregnant?

I’m 125 lbs and 18 weeks. I’m seeing that most women are exercising during pregnancy but I work full time and am constantly on my feet at work so I don’t see how I could find the time or energy! This is my first and I feel so guilty like I should be trying harder for the sake of me and my baby. Am I the o my one not working out in pregnancy? I should mention I was not working out pre-pregnancy either..