Working out

Be
Ladies I wouldn't say I worked out religiously before I decided to conceive- but I at least worked out 3-4 days a week.. Running included. I am having severe withdrawals bc I can notice I'm starting to gain a tad of weight- which is fine but I see it most in my legs! I'm a little under 6 wks pregnant and I'm terrified to do anything ! And honestly haven't had much energy- but I already miss it. Should I go ahead and start back now & take it easy in the gym or wait til 12 wks.. Dr told me I could run but no squats or lunges bc it could work out your abs... But I feel like running would do the same! ANYWAYS I just want some advise !