Hi everyone! I am new to this forum and to dieting. I am 5"2' and used to weigh 138 pounds. I managed to lose 13 pounds in 5 weeks through a strict diet of 1350 calories and doing cardio and strength training 3-5xs a week. I am not seeing any fat loss, and my jeans still fit roughly the same. I only know that I must have lost some body fat because I wore a dress today that used to be tight on me rather comfortably Can anyone share their experience on when they saw fat loss? Thank you!

P.S. - I didn't take before and after pictures when I started working out. It didn't occur to me, but I did take some a week ago.

Your weight is in the healthy range, so go you! But I think for most, weight loss gets increasingly difficult once you reach the healthy range. It's not just about cutting calories and generally exercising, you have to be really strict to see fat loss. You will in fact probably gain weight if you're looking to get a really athletic body. But I've read everywhere I go "abs are made in the kitchen." I know you don't mention abs specifically but it's just a general way of saying that WHAT you eat is more important than HOW MUCH you each. Also, with increased cardio/strength training you will find that you will need to eat more calories! Look into nutrition for sports, there will be articles and even a few books out there that will help you.

It is not that body fat loss is slow... Body fat can be metabolized as fast as your metabolism needs it. Rather, its that muscle gain is suuuuuper slow. Especially for women. If you lift weight quite heavily (and I don't mean those silly 5 pound dumbbells) you will be lucky to gain 1 pound of lean muscle a month.

1 silly pound!

And you need to gain muscle in addition to losing fat in order to see definition.
I started lifting weights 1 year ago.
So how does this relate to fat loss?
You are probably not "seeing" fat loss because your muscles need more time to develop. That creates definition and the look of having lost body fat. So right now, if you are in a calorie deficit, fat loss is certainly happening, its just that pound for pound, muscle cannot replace it as fast.

But for you, since you are already so small, it's going to take even longer to shed fat since you cannot healthfully create a very large deficit per day. From what you have described, your dress fitting differently, but pants the same, sounds about right in your time frame. In fact, I bet your pants fit differently, you just don't notice
Just be patient and lift more weights!