Exercise and weight loss during pregnancy..

Hi all, I'm on my 3rd week of my weight loss journey (it was very much needed) and I have just found out I am pregnant. I don't have an appointment with my dr until 3rd Jan so I can't ask yet but does anyone have experience with this? Is it safe to carry on? I'm not cutting things out (besides sweets and fizzy drinks). I am portion controlling, and trying to drink loads of water and walk around more. I had planned on starting the gym but is that now out of the question?

Any advice is much appreciated xx