Lunges and Squats

Vivian • I`m 32, a wife, a mom of an 8 year old boy, 4 year old girl and a 1.5 year old girl, full time teacher and a Christian.
What are the advantages and disadvantages to squats and lunges? My doctor told me no burpees (of course), no squats and no lunges. I have been working out since January and have been doing all of those since then. BUT I had a miscarriage in April. I'm now 5weeks and 4 days pregnant. Studies show if I want a natural birth, I need to do at least squats. Currently, I do Crossfit and they do a lot of squats and lunges. Please give me some insight on both the good and the bad of these workouts.