Loosing weight - first trimester

Is it safe to loose weight in the first trimester or to maintain weight until the very end of my pregnancy? I am 7 weeks pregnant with my second and I’m super conscious.

With my first I maintained the same weight until around 23 weeks (I’m just over 5ft and weighed about 9 stone) and also didn’t start to get my bump til around the same time too - my bump was so neat and my belly went down straight after birth and I was also able to yet back in all of my clothes.

Fast forward to my second, which is also after 1 year plus of lock down/covid restrictions. I have put on weight, I’m not sure how much exactly and although I can still get in all of my clothes they are no so comfortable and I’m super body conscious. With no scales and not really wanting to get on them either I’m saying possibly around a stone has been gained (maybe more maybe less) but I’m just wondering if there’s any chance I could loose any of it without harming the baby? Can I go on a certain diet? What exercise can I do? The weight is all over - thighs, upper arms, belly, hips, face - Any help I’d be very grateful for...thank you in advance x